Sivili Inzhiniyeringi May 2008 Vol 16 No 5
P CA A W A R D S W I N N E R 2 0 0 7 FOR EXCELLENCE IN MAGAZINE PUBLISHING AND JOURNALISM
The design of Durban Harbour’s new entrance channel Temperature and wear of rails on railway track Managing continuously welded rails the elegant way Gautrain construction update Ross Parry-Davies: Trailblazer in geotechnics 25 MONTHS TO FIFA 2010
P CA A W A R D S W I N N E R 2 0 0 7 FOR EXCELLENCE IN MAGAZINE PUBLISHING AND JOURNALISM Tshivenda ON THE COVER Specialist civil and geotechnical engineering contractor Esor Limited has played a key role in regeneration projects in the Johannesburg CBD, most recently for the new Absa mega office complex, the Universal Church of the Kingdom of God and a property development for Zurich Insurance Company (formerly SA Eagle) On the cover
Esor omnipresent in Johannesburg CBD regeneration 46
RAILWAY AND HARBOUR PEOPLE Trailblazer in geotechnics 48 ENGINEERING On the move 56
Published by SAICE/SAISI The design of Durban Harbour’s Block 19, Thornhill Office Park, Bekker Street, Vorna Valley, Midrand CONCRETE MATTERS Private Bag X200, Halfway House, 1685 Cellulose fibre reinforced cement fails University of Tel 011-805-5947/48, Fax 011-805-5971 new entrance channel 2 http://www.civils.org.za Pretoria strength tests as a gravity piping material 57 [email protected]
Editor Temperature and wear of rails on railway track 8 Sarie Moolman [email protected] Tel 012-804-2754, Cell 082-376-2652 LANGUAGE FOCUS: TSHIVENDA Managing continuously welded The role of civil engineering in a Editorial Panel Elsabé Kearsley (chair), Irvin Luker (vice-chair), Johan de changing environment 64 Koker (president), Wally Burdzik, Huibrecht Kop, Jeffrey Mahachi, Jones Moloisane, Hermien Pieterse, Eben rails the elegant way 16 Rust, Marco van Dijk, Michelle Theron, Sarie Moolman (editor), Barbara Spence (advertising), Verelene de Koker (secretariat), Dawie Botha (executive director), IN BRIEF 28 Zina Girald, Marie Ashpole The philosophy behind cost-efficient Sika strengthens Hermanus breakwater precast toskane Annual subscription rate SA R560,00 (VAT included), International US$120,00 track maintenance 23 Region looks towards Zimbabwe’s power plants Advertising Head office campus for Department of Foreign Barbara Spence, Avenue Advertising [email protected] Affairs Important trends in qualifications awarded Tel 011-463-7940, Fax 011-463-7939 Gautrain sleeper delivery on track 29 Cell 082-881-3454 to women and black learners Government should
Design and reproduction be more proactive in doing background screening Marketing Support Services, Menlo Park, Pretoria Gautrain construction update 31 on employees Annual IMESA conference call for Printing papers Nigeria: the desert is fast encroaching, but Ultra Litho, Johannesburg Giant tunnel borer to be dismantled when The South African Institution of Civil Engineering why? Ecological coastal city in China evokes the accepts no responsibility for any statements made or opinions expressed in this publication. Consequently Dutch Wadden Sea Balancing graduate oversupply nobody connected with the publication of the magazine, reaching the end of the tunnel 38 in particular the proprietors, the publishers and the and the SA skills shortage Liviero shows its editors, will be liable for any loss or damage sustained by any reader as a result of his or her action upon any mettle on the Gautrain Solar-powered automatic statement or opinion published in this magazine. Exciting coastal development at Gansbaai 43 lawnmower! Upgrading of Sandkraal Road, George ISSN 1021-2000 New high-tech crane set to double BLISHE PU RS E N I Z SAICE AND PROFESSIONAL NEWS A
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M F loading capacity Diarise this! 80 O 45 N A I O S S O C I AT Civil Engineering | May 2008 Text Sahil Patel Engineer, Prestedge Retief Dresner Wijnberg (Pty) Ltd [email protected] Anton Holtzhausen Director, Prestedge Retief Dresner Wijnberg (Pty) Ltd [email protected]
RAILWAY AND HARBOUR ENGINEERING
The design of Durban Harbour’s new entrance channel
The entrance channel of the Port of Durban is at present being widened and 1 deepened to provide access for vessels up to an equivalent size of a 9 200 TEU container ship within internationally accepted navigational safety and channel availability norms. On completion, the Port of Durban – and South Africa – will occupy a favourable position on the north–south global trade route and will help to grow local and regional economies into the future
AS A NATURAL ESTUARINE Edward Innes, who in 1890 directed HARBOUR, at the confluence of many the completion of the north and south trade routes, the Port of Durban has breakwater. Minor extensions, altera- developed into South Africa’s busiest tions and maintenance work have been multi-service port, handling a variety of carried out since, with the entrance commodities and vessels. channel still serving the port some 100 For the port to remain globally years later. competitive, Transnet has embarked on The main objective of the project a series of large-scale infrastructural is to provide the Port of Durban with developments. Of these, the deepening a new entrance channel which allows and widening of the entrance channel to for the safe access of all vessels up to an the port of Durban is the first and forms equivalent size of a 9 200 TEU (twenty- the catalyst for further expansion within foot equivalent) container ship (length = ments included navigational safety for the port. 350 m, beam width = 45,6 m and draft = vessels using the channel and a high The development of the harbour 14,5 m) under most weather conditions. degree of availability for all vessels up to breakwaters dates back to the 1840s The design of the new entrance – and including – the design ship. These through to the 1890s under the stew- required consideration of a number of requirements were to be met without ardship of civil engineers John Milne, functional and port operational require- inducing additional sedimentation of the Captain James Vetch and eventually ments. The primary functional require- channel, minimising the adverse impact
Civil Engineering | May 2008 of increased wave energy on the adjacent 1 Entrance channel to the Port of Durban 2 Bluff and Point berths, and maintained 2 General layout of proposed works within the available land, utility and en- 3a 1:100 physical model of Durban’s vironmental constraints. In addition, the entrance channel design was required to allow shipping 3b Model bulk carrier moored at Bluff berth 4 traffic into the port during construction on a 24-hour basis without undue con- treline being slightly realigned. gestion. The design depth of a navigation channel is aimed at providing safe ac- PROJECT DETAILS cess to the port under all operationally Prestedge Retief Dresner Wijnberg (Pty) acceptable conditions. Allowances for Ltd (PRDW), supported by the Council sedimentation, vessel trim, survey ac- for Scientific and Industrial Research curacy, squat and nominal underkeel (CSIR), in physical modelling and navi- clearance were made in accordance with gation assessments, were appointed in PIANC international guidelines. The October 2002 by Transnet National channel depths were verified by means of Ports Authority to undertake the feasi- a numerical vessel motion model which bility study. PRDW were then appointed is used to calculate wave-induced loads in February 2006 to carry out the detail and motions. design of the deepening and widening of During the preliminary design stage the harbour entrance channel. the SIMFLEX mini bridge-view simu- 3a The existing channel is orientated lator was used to validate the concept in the direction of the dominant winds, design layout which initially indicated The design of Durban Harbour’s that is, south-westerly to north-easterly. a channel bottom width of 190 m. The The channel has an advertised depth of outcome of the ship manoeuvring study −12,8 m CDP (chart datum port) and a was a recommendation to increase the bottom width of 121 m at its narrowest. bottom width to 220 m. This new layout new entrance channel The depth is restricted by the presence of width was verified and validated by a a sub-aqueous tunnel passing under the second SIMFLEX mini simulator study entrance channel and carrying municipal followed by a full-mission study car- water, sewerage, electrical, communica- ried out at the South African Maritime tion and other services. Training Academy (SAMTRA) in The width of the existing entrance Simonstown. channel is well below internationally The deepening and widening of the recommended guidelines for the safe harbour entrance was initially consid- handling of vessels, which is further ered to affect the berths immediately complicated by the presence of strong adjacent to the entrance channel by 3b cross-currents (up to 2 knots) at the allowing increased wave energy penetra- entrance. It is largely due to the skills tion. Studies were therefore undertaken of the Durban harbour pilots that large to assess the impact of the project on the sea-going container vessels up to 4 000 functionality of these berths (berth 4 on TEU, car carriers, tankers, and bulk car- the Bluff and A berth at the Point). riers can be safely manoeuvred into the A 1:100 scale model of the entrance harbour, albeit at somewhat elevated risk channel area was constructed at the levels. hydraulics laboratory of the CSIR in The wider and deeper entrance Stellenbosch. Two basic layouts were channel required the construction DESIGN COMPONENTS tested, namely the existing layout and General layout the proposed new layout. A set of wave of a new north groyne. The During the preliminary design phase scenarios was propagated from the primary function of the new a number of channel alignments and model offshore boundary into the har- layouts were considered in response to bour and, using a digital video system, north groyne was to dissipate the functional requirements as defined moored ship motions were recorded at wave energy, prevent the ingress by Transnet’s National Ports Authority. the affected berths. By repeating the These layouts were subjected to a multi- same wave conditions, the relative dif- of sediment into the navigable criteria assessment based on navigational ference in wave penetration and ship channel, and protect the banks and safety, impact on existing berths, land motions, as recorded in the two model uptake, environmental impacts and layouts, was quantified. basic service ducts in the area capital costs. The preferred layout gave The ship motion results were com- preference to the re-construction of a pared with international guidelines new north groyne with the channel cen- which indicated that no significant
Civil Engineering | May 2008 4 Channel side Sea side +4,5 m CDP Concrete cap
Concrete cubes Rock armour 0,05 m CDP Natural seabed profile Rock armour Core
Rock protection
−19,0 m CDP
Rock filter
6 5 For the study a 1:100 scale 3D hydraulic model of the entrance channel was constructed to test the stability of the groyne against the 1:100-year storm event. This design storm event was deter- mined by using measured wave data and a numerical wave propagation model, where wave heights were transformed to a location 150 m off the head of the proposed new north groyne. The design 4 Typical cross-section of new north groyne significant wave height for the head of 5 Regular overtopping experienced the groyne was determined as 3,3 m, on south breakwater whilst a significant wave height of 1,3 m 6 Large cracks are evident on the was used for the design of the revetments concrete cap of the south breakwater on the trunk of the structure. These wave 7a and 7b Physical model of south breakwater heights are indicative of the sheltered with dolos and antifer armour units position of the new north groyne, which 8 Demolition activities on the north bank is located in the lee of the existing south 7a 9 Graphic illustration of how a trailer breakwater. suction hopper dredger operates South breakwater reinforcement change in berth availability would occur Construction of the south breakwater as a result of the proposed widening and commenced in 1885 and was largely deepening. completed by 1907. An extension of the structure by approximately 200 m was New north groyne completed around 1932. As-built records The wider and deeper entrance channel are vague with historical figures sug- required the construction of a new north gesting a shallow foundation for the orig- groyne. The primary function of the new inal structure. Subsequent sand bypass north groyne was to dissipate wave en- dredging implies much deeper depths ergy, prevent the ingress of sediment into at the toe of the structure and potential the navigable channel, and protect the additional construction activities leaving banks and basic service ducts in the area. significant uncertainty regarding actual The optimum length for the new as-built details. At this stage continued north groyne was determined to be wave attack necessitated repairs that was 7b 550 m with a maximum depth at its constructed using 20 t dolosse. Figure 5 seaward end of −17,5 m CDP. The groyne shows heavy overtopping of the structure comprises graded rock, concrete armour during a storm wave attack. units and a mass concrete cap with a The present structure shows a fair crest height of +4,5 m CDP. The concrete amount of damage and steep slopes along armour units include 20 t dolosse as well the channel side. Since the completion of as 5 t and 10 t antifer cubes. A typical the breakwater head, the cap has settled cross-section of the new north groyne is vertically by up to 0,7 m in places, re- shown in figure 4. sulting in large cracks (figure 6). As part The main tool for verifying a break- of reinstating the concrete cap, its width water design is physical model testing. was extended to allow access for cranes
Civil Engineering | May 2008 up to a capacity of approximately 700 t. channel. In most cases, as-built drawings 8 Flexibility has to be maintained in were sourced from Transnet National terms of future sand bypass operations Ports Authority and photographic which may require accommodating records from eThekwini Municipality. more eroded toe levels than typical Quite a number of structures and serv- historic values. The proximity of dredge ices had no formal records, however, and boundaries to the breakwater toe and an extensive on-site investigation had to unpredictability of dredge slopes due be undertaken to fill in the gaps. to coastal processes requires that the The demolition site is approximately new toe be founded at least at the same 150 m wide by 900 m long and occupies depth as the existing structure. Existing some 10 ha. The site is zoned as light toe levels will be determined by detailed commercial and consists mainly of old jet probing executed as part of the con- cargo sheds and workshops that have struction contract. The rock toe is to been converted into restaurants and be constructed immediately after this other tourist attractions. The demolition excavation has taken place to avoid sand works consist of the following: accretion compromising breakwater toe ■ Removal and disposal of asphalt and levels. Toe dimensions were confirmed concrete paving in a two-dimensional model study where ■ Demolition and removal of various vertical settlement of up to 5 m seaward building types, including standard of the toe was simulated. brick structures, old military gun em- The results of model tests indicated placements, port buildings and sheds/ that changes in the bathymetry due to a warehouses deepened entrance channel would lead ■ Demolition and removal of various 9 to increased wave attack on the head of port structures, including quay walls, the south breakwater as a result of wave concrete caissons and concrete rubble focusing. PRDW were requested to carry ■ Removal of the old north breakwater out a design to reinforce the south break- comprising rockfill, concrete blocks water in order to ensure its reinstate- and general fill material ment to a standard corresponding to that Demolition products, concrete, layer- of a new structure. works, etc, were used in the construction Owing to the increased wave attack of the new north breakwater to reduce on the head of the structure due to wave the imported fill content and to mitigate focusing, the damage levels were beyond potential traffic impacts. Figure 8 shows acceptable design norms even after in- the progress made on the demolition creasing the dolos size from 20 t to 30 t. works. The results of model tests indicated In order to reduce wave focusing, con- that changes in the bathymetry due figuration dredging (seaward of the head Dredging of the breakwater) was incorporated, but By law, marine disposal of dredged to a deepened entrance channel this did not solve the problem entirely. material is subject to the approval of would lead to increased wave attack Increasing the dolos size beyond 30 t is the division of Marine and Coastal considered impractical due to the risk of Management (MCM) of the Department on the head of the south breakwater breakages. In addition, the potential for of Environment Affairs and Tourism. as a result of wave focusing armour settlement in response to unpre- This, in turn, is governed by interna- dictable toe settlement or the potential tional conventions to which South Africa of discovering unexpected breakwater is a signatory. The dredging and disposal profiles during excavation of the toe sug- permits were granted for the project in gested a need for robust units that would February 2007 with a validity of two not break under such settlements. It was years. therefore decided that large antifer cube The existing marine disposal area units with a mass of 45 t would be used (some 6,26 km2), as used for annual main- along with configuration dredging. These tenance dredging in the port, formed the units were tested and validated in the basis of the application, with the planned three-dimensional physical model at the disposal of up to 10 million m3 of dredged CSIR hydraulics laboratory. spoil. If uniformly distributed over this area, the dredged material would raise Demolition the seabed level by an average of 1,7 m. The demolition works involved the re- The minimum water depth over the area moval of buildings and port structures is 70 m, so the change in bathymetry will along the northern bank of the entrance not cause any measurable effect on wave
Civil Engineering | May 2008 characteristics, nor will it have any impli- mised by ongoing monitoring at critical cations for navigation. locations and regulation of the contrac- The most significant impact of the tor’s activities when threshold levels are dredging and breakwater construction approached. work is potentially its adverse effects on The bulk of the dredging work will water quality, and specifically turbidity be undertaken using a trailer suction and suspended solids and the release of hopper dredger. Removal of isolated rock harmful constituents from the sediments outcrops, and clearing of debris from into the water body. This impact is mini- the old north groyne structure, will be
10a
The most significant impact of the dredging and breakwater construction work is potentially its adverse effects on water quality, and specifically turbidity and suspended solids and the release of harmful constituents from the sediments
into the water body. This impact is 10b minimised by ongoing monitoring at critical locations and regulation of the contractor’s activities when threshold levels are approached
PROJECT TEAM Client Transnet Capital Projects acting on behalf of Transnet National Ports Authority Lead design consultants Prestedge Retief Dresner Wijnberg (Pty) Ltd EPCM contractor HMG Joint Venture and involvement with technical supervision by Prestedge Retief Dresner Wijnberg (Pty) Ltd Main contractor Dredging International/ Group 5 Consortium Contract value R3,2 billion Contract duration 150 weeks
Civil Engineering | May 2008 achieved by a large backhoe dredger, progress is shown in figures 11a and The project is expected to be com- loading into hopper barges for marine 11b). Dredging by trailer suction hopper pleted by March 2010. disposal. dredger and split hopper barge is also in progress. To date, 4,5 million cubic me- Acknowledgement PROJECT STATUS tres of a total of 10 million cubic metres Prestedge Retief Dresner Wijnberg (Pty) Ltd The main contractor for the entrance has been dredged and disposed offshore would like to acknowledge Transnet Capital channel project, Dredging International/ at the specified disposal site. In March Projects and Transnet National Ports Authority Group 5 Consortium, was appointed 2008 the construction of the new north (Durban) for supporting this article. under the NEC 2 ECC option B form groyne was about 10 % complete and the of contract and mobilisation began in reinforcing of the south breakwater was May 2007. The removal of the existing well under way. A total of 2 240 precast 10a and 10b Dredging International’s trailer north breakwater as well as the demoli- armour units with a mass ranging from suction hopper dredger Marieke on site in Durban tion of the north bank is under way (the 5 t to 45 t have been manufactured. 11a and 11b Construction in progress: March 2008
11a 11b
Civil Engineering | May 2008 Text Johan de Koker University of Johannesburg PO Box 6064, Ansfrere, 1711 [email protected]
Temperature and wear of rails on railway track
In this article, the author attempts to describe the wear mechanism in the TRAINS DO NOT HAVE steering interface between the wheel flanges running against the side of the rail wheels. They stay on track by means of the guidance provided by the wheel crown when a railway wagon rounds a curve in a railway line. The cost flanges. When the train rounds a curve of aggressive wear in the rail–wheel interface is compared to the cost of the wheel flange bears against the side of the high leg rail crown, causing fric- lubrication of the railway track and methods of lubricating the rail-wheel tion and wear. Since this is direct steel interface are described briefly. The trajectory of points on the wheel to steel abrasive contact at speeds of up to 100 km/h with lateral forces of flange against the side of the rail is described and the effect of aggressive 3 t to 6 t and more, this wear could be wear between the surfaces shown. The results of measurements of rail substantive on both the side of the rail crown and the wheel flange.1 temperatures in the wear interface are discussed, as well as the frequency THE COST OF WEAR of occurrence of hot wheels on the Richards Bay coal export line When the rail–wheel interface is lubricated, the wear rate decreases 1 substantially: a dry wear rate of 0,127 to 0,178 mm/MGT (million gross tonnes of traffic) was measured in controlled tests.1 Lubricating the rail–wheel interface moderately well (medium enforcement) resulted in a wear rate of 0,0074 mm/MGT (17 times improve- ment) and good lubrication (high level of enforcement) resulted in 78 times (7 800 %) reduction in the wear rate to 0,0016 mm/MGT. These measurements were done under well-controlled test and evalu- ation conditions at the Facility for
Civil Engineering | May 2008 Accelerated Service Testing at the the fling-off of applied lubricant from QUANTIFYING LUBRICANT APPLICATION Transportation Test Center of the the wheel flange causes the section of In closed systems such as gearboxes Association of American Railroads in the bogie frame around the wheel to be and, to a lesser extent, bearings, the Colorado.5 The economic value of this covered with grease and to become very working and wearing parts run within reduction in wear and saving in replace- dirty. Therefore the devices are frowned a reservoir of lubricant, and starvation ment cost of rail and wheels is huge. upon by the locomotive maintenance of lubricant only occurs in very excep- To replace the 182,5 km of high leg staff and do not get maintained as they tional cases. The lubrication of rail and curve rail on the line carrying loaded should. wheel flanges, on the contrary, can very coal traffic between Blackhill and An alternative method of lubrication easily deteriorate to a starvation situa- Richards Bay will cost R103 million is to use trackside lubrication devices tion where the lubricant becomes insuf- (at 2007 rail prices). If not lubricated usually installed at the beginning of ficient. It must therefore be ensured at all, the rails on curves would have some curves. The grease pumps are ac- that lubricant is replenished regularly, to be replaced after carrying 30 MGT, tivated by the wheel tread and grease is and a relatively thick grease film acts as that is after 146 days (five months) at pumped out on a wiper bar on the in- lubricant reservoir in this application. an average cost of R705 000 per day, side of the rail crown where the passing However, if too much grease is applied labour cost excluded. If the line is lu- wheel flanges pick it up and deposit it in to the wheel, excess grease is flung off, bricated well and allowing for only 50 a reciprocating action on the wear face causing environmental concerns, and times’ improvement, replacement of of the curves ahead.3 This system used excess grease also tends to creep onto the rail is delayed to every 7 300 days to be favoured by Transnet, and at one the running surface of the rail. This can at on average cost of R14 000 per day. stage they had about 5 000 trackside cause traction problems with resultant The cost of application of lubricant is machines around the country, span- skidding and damage to the rail running R6 000 per day, but the daily saving in ning 20 000 km of track all over South surface.2 rail cost is about R685 000. The cost of Africa. However, since these machines With rail and wheel flange lubrica- re-profiling and replacement of wheels are out on the track, exposed to the ele- tion, grease has to be replenished on a is not included in this calculation, but it ments and all weather conditions, they regular basis since all the grease is lost is generally accepted to be about double are labour intensive to maintain, and and consumed. Because the lubrication that of rail! the management of the maintenance system is extended over many kilometers process is expensive and cumbersome. of varying environmental, track geom- LUBRICATING WHEEL On the Richards Bay coal export line etry, traffic and operating conditions FLANGES AND RAILS and some of the main lines, a system it is extremely difficult to measure and In practice, problems are usually expe- is now used where dedicated vehicles control all the factors influencing the rienced with efficient application of the with on-board lubricating equipment system. The traffic profile, quantity and lubricant to the rail–wheel interface. run on the track at regular intervals and speed differ from day to day. Quantifying Various methods of lubrication have deposit a bead of lubricant on the wear the application rates is some times more been developed and are applied on dif- face of the curves. This system, though of an art than pure science. ferent railway systems. more costly than the trackside system, Fitting lubrication devices on the produces good results if managed prop- 1 Train wheels showing the wheel locomotive wheels is not favoured in erly. The vehicle also doubles as a patrol flanges on a Richards Bay Coalline rail South Africa. The locomotives oper- vehicle to identify problem spots on the 2 A well-lubricated wear face ating on the South African 1 065 mm track. However, the downside is that on the side of the rail crown gauge lines have very little space for it occupies a slot in the schedule that 3 A dry, wearing rail. Note the pitting additional devices on the bogies, and could have been utilised by a train. wear marks on the side of the rail crown
2 3
Civil Engineering | May 2008 4 4 The path of particles on the wheel at various distances from the running surface plotted on the rail if the wheel flange and rail side were vertical 5 Close-up of rail wear surface showing fatigue cracks with traffic direction from left to right and the angle of cracks 111˚ (69˚) with the horizontal. Calibration at the bottom is in millimetres 6 Close-up of gouges caused by aggressive wear followed by a period of lubrication, in the contact area between the wheel flange and the rail. The calibrations at the bottom 5 and on the right hand side are in millimetres
An attempt was made to calculate the grease application rate on the Richards Bay Coalline by taking the fig- ures available for the section Ntlasatse to Richards Bay, a distance of 137 km of double line consisting of about 48 % curves. It is assumed that 131,52 km of curve was lubricated every day, the section being lubricated six out of seven days. Over 326 lubricating days, 68 drums (180 kg each) were used, and it is estimated that 10 kg of grease per drum goes to waste due to poor transfer and wastage practices. A total of 11 560 kg of grease was therefore applied over 326 days on 42 875,5 km of curve, consumed by an estimated 10 700 axles every day. This reduces to 0,2696 kg grease applied to each kilometre of curve, al- ternatively, 3,709 km of curve consumes 1 kg of grease. This gives 0,0252 gram/
6 km curve/axle/day. OBSERVATIONS REGARDING THE WEAR OF THE RAIL Since the tread of the train wheel runs in rolling mode on the running surface of the rail, the wheel flange slides over the side of the rail. If the wheel flange were truly vertical, the path of a par- ticle on the wheel over the rail would resemble that of a parabola where the particle would be in contact with the rail the whole time while describing the parabola. Since the wheel flange to side of rail contact surface is a complex ‘s’ curve, sliding contact does not occur over the full face of the rail but in small spots on the wear face, depending on the profile of the particular wheel, that is, whether it is a new or an old, worn wheel. Asperities and any high spots would bear the brunt of this contact. If the surface is well lubricated, the sliding contact, with a lateral force
10 Civil Engineering | May 2008 from loaded coal trucks of up to 6 t of the rapid cooling process it would The coarse, worn surface on the (nearly 60 KN), does very little meas- be martensitic in structure and could wheel flanges scoops up the last ureable damage to the rail, resulting gouge out more steel from the wear sur- in a smooth, work-hardened wear face before falling out. remnants of lubricant on the rail surface with fatigue cracks forming The coarse, worn surface on the and the lubricant film is decimated over time. The angles of these cracks wheel flanges scoops up the last rem- differ from curve to curve, depending nants of lubricant on the rail and the rapidly. The pieces of steel gouged on the traffic conditions and speed. lubricant film is decimated rapidly. out of the rail and wheel flange Cases were sighted where the cracks The pieces of steel gouged out of the were at about 90˚ with the horizontal rail and wheel flange surface fall and surface fall and collect on the foot of where the traffic was running in both collect on the foot of the rail and the rail and around the extremities directions over the rail. However, on the around the extremities of the mag- Richards Bay Coalline, where there are netised rail fasteners on electrified of the magnetised rail fasteners on dedicated lines for up and down traffic, track. These shiny particles are nick- electrified track. These shiny particles it was found that the fatigue cracks were named ‘moondust’ or ‘rail dandruff’ sloping with the direction of traffic (see because of their shape, colour and size. are nicknamed ‘moondust’ or ‘rail figure 5). The angles with the horizontal Unfortunately, once this aggressive dry measured between 62˚ and 78˚, with wear sets in, the damage to the rail and dandruff’ because of their shape, the average around 68˚. The cracks wheel flange surface is severe. colour and size. Unfortunately, measured between 0,5 mm and 1,0 mm Inspection of some of the close-up apart. rail wear photos seems to reveal small once this aggressive dry wear sets It is suggested that fatigue cracks nodes of rail steel heated to discoloura- in, the damage to the rail and first form at the colony boundaries tion suggesting temper colours: straw- of the pearlitic rail steel. Because of brown and blue. wheel flange surface is severe this divergent lamellar structure of the individual pearlitic colonies, the RAIL TEMPERATURE MEASUREMENTS deformation behaviour is different in In an attempt to quantify the frictional each pearlite colony and therefore high forces, it was decided to measure the stress concentrations will occur at these rise of the rail temperature as close as boundaries during plastic deforma- possible to the wear surface of the rail tion. When the yield stress is exceeded, while at the same time measuring the fatigue cracks will form at the cluster lateral forces and wheel loads. A suit- boundaries due to the anisotropy able curve was chosen on the Richards (having different physical properties in Bay Coalline at 59/9 km south of different directions) of the clusters.6 Vryheid and instrumented. The curve As the train traverses the rail, small had a radius of 604 m, super-eleva- pieces of steel worn off the running tion of 20 mm and a design speed of surface or the gauge corner radius 50 km/h. Temperature was measured area of the rail, or from the cracked, with a thermistor embedded into a fatigued surface of the side of the rail, groove filed into the rail wear surface would wedge into the sliding contact on the gauge side of the rail crown. The area between the wheel flange and the vertical wheel loads, lateral wheel loads rail. If this happens when the interface and speed were derived by measuring is well lubricated, the intrusive steel the shear strain in the rail with strain particle is protected from friction and gauges. The coefficient of friction was overheating by the lubricant and rolled measured with a manually operated into a relatively harmless thin, flat steel tribometer manufactured by Salient particle within the lubricated wear face. Systems and the ambient temperature However, if this happens when the rail- was measured with a rail thermometer. wheel interface is dry or when lubricant The train and truck data (number and starvation occurs, the full lateral force type) were obtained from the central- from the wheel would be concentrated ised traffic control office in Vryheid. on this unprotected little piece of All the parameters were recorded over a steel. It would be squashed, rubbed three and a half day period for a total of and heated very rapidly between the 57 trains that passed over the test site. wheel and the rail due to the lateral and The line had not been lubricated for the frictional forces. It would momentarily last 20 km and it was assumed that this weld itself to the rail and wheel, cool would enable the line at the test site to down and tear a piece of metal out of be dry and the lubricant totally con- both or one of the surfaces. As a result sumed by the third day.
Civil Engineering | May 2008 11 7 surface. All the other thermocouples were glued onto the surface of the rail. A twelfth thermocouple was embedded in the surface of the low leg rail (similar to the one shown as 3 in the high leg) right opposite the instrumented high leg rail. All the thermocouples were + linked to an HBM MGC amplifier to record the temperatures.4 The objective of the measurements was to establish the relationship be- tween the rise in rail temperature in the gauge corner rail–wheel interface induced by passing trains and the established coefficient of friction and train parameters such as speed, mass, number of wagons or the bogie type. Hence, many graphs were prepared by one of the team members to study any possible correlation between these vari- ables. No meaningful correlation was No meaningful correlation was A rise in rail surface temperature of found between the increase in rail tem- found between the increase in rail up to 12 ˚C was recorded under loaded perature and the coefficient of friction, 200-truck coal trains, and the coeffi- speed of the trains, average axle load of temperature and the coefficient of cient of friction was recorded to be from the train or average lateral load on the friction, speed of the trains, average 0,18 the first day to 0,37 on the last high leg rail. day. However, the rail was never really A strong correlation was found axle load of the train or average dry since a small amount of lubricant between the length of the train and the lateral load on the high leg rail. was carried over from beyond the non- increase in rail temperature. lubricated portion of track. The coef- For trains of the same type, travel- A strong correlation was found ficient of friction did not regress in a ling at similar speed, the temperature between the length of the train and linear fashion since it was observed that did not increase with higher coefficient grease was carried over larger distances of friction on the wear surface of the the increase in rail temperature by some wheels, probably depending high rail. However, it is thought that on wheel profile and tracking ability of the condition of the bogies could be the some bogies. controlling factor.4 When the data were analysed, a very The average increase in wear face good correlation was found between the temperature was 0,000506 ˚C per tonne rise measured in rail temperature and for 200-truck trains with 100 tonne per the cumulative lateral force. It was as- truck payload, 0,000529 ˚C per tonne sumed that this temperature rise could for mixed 200-truck coal trains and be attributed to the frictional forces 0,01019 ˚C per tonne for 50-truck gen- between the wheel flange and the rail. eral freight trains.4 Owing to the promising data collected, A graph of temperatures measured it was decided to return to the site to under a fully loaded 100 ton per truck repeat the test, provided that the rail train shows some interesting features: could be kept dry to see what tempera- ■ All the measurement points (thermo- ture rise could be achieved. couples), even those at the foot of the The second battery of tests was done rail, show a rise in temperature at the at the same site during August 2006 beginning of the passing train. It is with eleven temperature probes (ther- surmised that this rise is due to the mocouples) mounted on the high leg rail heat produced by the passing locomo- as shown in figure 9. This was done to tives measure the spread of the heat through ■ The thermocouples closest to direct the rail. The thermocouples in danger of contact with the wheel, that is num- being damaged by passing trains (num- bers 3, 4 and 5, show the most imme- bers 3 and 4) were embedded in the rail diate and highest rise in temperature by glueing them into grooves ground ■ The thermocouple on the surface of into the rail on the rail-wheel contact the low leg, number 12, shows an un-
12 Civil Engineering | May 2008 8a 8b
9 10
Field side
Gauge side Accumalated lateral loads
Time (sec)
Test number 057 – Accumulated lateral force (greater than 7 t) + Temperature Superimposed – 100smalls/100jumbos – M = 18 274 t / 52,3 km/h
expected high rise in temperature tures of all passing trains are measured 7 Wear particles collecting around the The unexpected and simultaneous rise by means of measuring devices set up rail fastening due to electromagnetism in temperature in the surface of the next to the railway line. These are non- 8a and 8b Microscopic view of wheel-rail low leg rail was found to be fairly close contact measuring devices measuring wear debris lifted from the rail wear face to that of the high leg. When this was the wheel temperatures either at the 9 The correlation between the rise measured in investigated, it was found that this rise central bearing area of the wheel or at rail temperature and the cumulative lateral force in temperature can only be attributed the peripheral or tyre area of the wheel. 10 The positions of the thermocouples to heat induced in the rail from the If a wheel bearing fails, it will overheat mounted on the high leg rail running surface contact between the and in extreme cases lead to a derail- rail and hot wheels. This is partially ment with resultant costly damage to nance to be performed. borne out by the good correlation found the rolling stock as well as to the track. Wheel tyre temperature measure- between the length of the train (number Similarly, if the friction brakes on a par- ments for 392 970 wheels (approxi- of wheels) and the increase in rail tem- ticular truck do not release after an ap- mately 480 trains) that passed one of perature. plication, the wheel tread and tyre heats the Coalline temperature measuring This unexpected result of the up and could result in the tyre coming devices between September 2006 and test led to an investigation into the off the wheel, also with a resultant very June 2007 were then analysed. measurement of actual wheel tem- costly derailment. It was found that the temperature peratures. Transnet therefore measures the of 1 % of the wheels measured above wheel temperatures in order to identify 220 ˚C, which is the flash point of the MEASURING WHEEL TEMPERATURES overheated wheels so that the wagons molybdenum disulphide grease used to On the Richards Bay Coalline, there are with these wheels can be taken off the lubricate the wear face of the rail/wheel a number of sites where wheel tempera- train to enable the required mainte- flange contact area. The number of
Civil Engineering | May 2008 13 11 11 The instrumented rails in August 2006 with the low leg rail in the foreground 12 Temperature measurements in the rail under a 200-truck fully loaded coal train 13 Percentage of hot wheels between 300 ˚C and 600 ˚C on the Richards Bay Coalline
wheels above 300 ˚C was calculated to be 0,214 %.
CONCLUSION These results explained the lack of correlation between the coefficient of friction and rail temperature rise in the temperature tests described in this paper. It also explained the high grease consumption on the line, and the fact that the grease disappears without trace. It seems that the grease is literally burned up. 12 References 26 1 De Koker, J J. The use of lubricants on T03 railway rails. South African Institute of
24 Tribology International Conference, Pretoria, July 2000. 2 De Koker, J J. Developing solutions to T04 22 T05 trackside lubrication grease spatter. 3rd )
C T06 ˚ Conference on Environmental Engineering, 20 South African Institution of Civil Engineering, KwaMaritane, 27–28 May 1999. 3 De Koker, J J. Rail and wheel flange lubrica-
Temperature ( 18 tion. South African Institute of Tribology T12 International Conference, ‘Tribology in 16 Mining’, Pretoria, 1992. 4 Fröhling, R, De Koker, J J and Amade, M. Rail lubrication and its impact on the 14 rail/wheel system. International Heavy Haul Association Conference, Kiruna, Sweden, 12 June 2007. 0 20 40 60 80 100 120 140 160 180 200 220 240 260 5 Reiff, R P. Rail/wheel lubrication studies at Time (sec) FAST. Lubrication Engineering (Journal of the American Society of Lubrication Engineers), 42(6), pp 340-349, June 1986. 6 Yokoyama, H, Mitao, S, Yamamoto, S and 13 Fujikakeb, M. Effect of the angle of attack of flaking behavior in pearlitic and bainitic steel rails. Wear, 253, pp 60–66, 2002.
0,07 This paper was presented at Tribology 2008, 0,06 the 9th International Tribology Conference, 0,05 which was presented by the South African 0,04 Institute of Tribology at the University of Pretoria 0,03
Percentage Conference Centre from 2 to 4 April 2008 0,02 0,01 0 301–350 351–4000 401–450 451–500 501–550 551–600
Temperature (˚C)
14 Civil Engineering | May 2008 Text P J Gräbe Chair in Railway Engineering Department of Civil and Biosystems Engineering University of Pretoria [email protected] R V Freyer Trackwork engineer Bombela Track [email protected] R J Furno Trackwork engineer Bombardier Transportation [email protected]
WILMA–Managing continuously welded rails the elegant way
A new intelligent rail stress THE ADVANTAGES of continuously Transnet Freight Rail system to monitor monitoring system has been welded rails (CWR) over conventional and manage CWR. The system was de- non-welded rails are well known and the veloped with the following aims: developed by Transnet Freight substantial reduction in total rail life- ■ To develop a wayside system that will Rail (Technology Management). cycle cost is certainly its most attractive monitor longitudinal rail stress in real benefit. However, CWR has to be man- time to enable better management of The system uses strain gauges to aged in such a way that the potential CWR ■ measure longitudinal rail forces track failures that accompany it do not To warn against possible track buck- relegate the safety of the track. ling and rail breaks as well as rail temperature. The Statistics of the coal export line ■ To be a tool for planning and ex- system is used to manage CWR, in South Africa revealed that some ecuting CWR maintenance 50–60 % of all train delays are stress ■ To prevent derailments but can also predict rail breaks related. Track stress is responsible or CWR MANAGEMENT and buckling, functions as a contributes to the occurrence of rail breaks, track buckling, block joint fail- Theory maintenance tool and can do ures, certain track geometry deviations Tracks with continuously welded rails and component failures in turnouts. have to be managed for the occurrence predictions based on historical This article describes an intelligent of residual rail stresses and bending measurements and weather system that has been developed to stresses caused by train loads as well as manage CWR on a heavy-haul line and temperature stresses which are respon- forecasts, thereby reducing train which has already been implemented on sible for rail breaks and lateral stability delays and derailments. a track section of 200 km. problems such as track buckling. The rail force (N) due to a tempera- The system comprises a valuable THE WILMA SYSTEM ture increase is calculated with the fol- contribution to the high-tech world WILMA is the acronym for Wayside lowing formula (from Esveld2): Intelligent Longstress Management and N = EAα∆T of heavy haul is the name that has been chosen for the In which:
16 Civil Engineering | May 2008 1 2
E = Young’s modulus for the rail, frame used by Transnet Freight Rail has 3 (N/mm2) however been upgraded to enhance ac- A = total cross-sectional area of curacy and performance. the rail (mm2) Strain gauging is extremely accurate α = coefficient of expansion (/˚C) and usable in any stress condition. It
∆T = Tneutral - Tactual (˚C) however requires a high skill level for The neutral (or stress free) rail tem- initial installation and is expensive. perature (Tneutral ) is the temperature at A critical evaluation of the methods which the track is neither in compres- mentioned above has been carried out sion nor tension. The rail force will then to develop the WILMA system that will be approximately 0. If the rail tempera- be described below. ture rises above Tneutral , the track will be in compression while a decrease in rail SYSTEM DESCRIPTION 1 Cover plates to protect instrumentation against vandalism and on-track maintenance temperature below Tneutral will result in The system is made up of the following overall tension forces in the track. components: 2 Hardware for CWR measurement The neutral temperature of the ■ Encapsulated strain gauges 3 System layout and concrete enclosure track can be measured by a number of ■ HBM MGC-Plus amplifier system methods. ■ HBM CP22 communication card installed in a steel cabinet placed in a ■ RS232-GPRS communication inter- concrete enclosure next to the track, Measurement methods face unit which is either a concrete cubicle or a CWR measurements are usually carried ■ Siemens Class10 GPRS Modem relay room. out on Transnet Freight Rail lines by All the strain and temperature gauges Figure 2 shows the hardware chosen using one of the following methods: are encapsulated for ease of application to amplify the rail stress and tempera- ■ Cutting the rail combined with hand and re-usage and are manufactured by ture measurements and which remotely measurements trained Transnet Freight Rail techni- sends the data to a central file server. ■ The lifting frame method cians adhering to strict quality control A standalone amplifier with a plug-in ■ Strain gauge-based measurements measures. display unit is utilised and can be ex- Cutting the rail combined with meas- Applied instrumentation is cov- panded to more than 20 measurement uring the rail movement is accurate if ered by cover plates to protect against channels. measurements are done correctly, but it vandalism and damage due to on-track The communications processor has requires track occupation, the welding maintenance procedures. The cover RS232 connectivity and is remotely of a closure rail and it weakens the track plates are manufactured from mild steel configurable via SMS. It connects to a structure. and are galvanised to prevent rust. Two server via GPRS to send data. Approved The lifting frame method is also matching cover plates are bolted onto lightning protection forms part of the a time-consuming procedure which each other from both sides of the rail to hardware that is housed in the steel requires track occupation to loosen and protect the rail bound instrumentation cabinet. fasten the rail fasteners and is only use- (see figure 1). Figure 3 shows the concrete cubicle able in tension conditions. The lifting The measurement hardware is with a safe door that is placed next to
Civil Engineering | May 2008 17 4 4 File server with monitoring software 5 Geographical Coalline map with measurement stations 6 Lifting frame for the calibration of the system
the track to house the measurement hardware. Strain gauge cables are sepa- rately threaded through steel reinforced hydraulic hosing which runs along the sleepers and then vertically down into the track formation where it is buried. From outside the track formation the cables are conveyed to the concrete cu- bicle in galvanised steel pipes. The last component of the system is the file server with monitoring software and large screen display (see figure 4). Data is received by the server and 5 stored in a database from where the monitoring software can access the real time measurements. (The software is described in detail later in the article.) The next section deals with the sys- tematic approach that was followed to select the measurement sites.
SITE SELECTION Sites were selected by interaction with track engineers and maintenance man- agers, by a desktop study of the call-out history of the line (including ultrasonic measuring car (UMC) faults and inci- dents that caused train delays) and by studying the general topography and layout of the line. Sites were selected on a priority basis and the following list gives an in- dication of how sites were prioritised: 6 ■ Tunnel entrances and exits ■ Track buckling and rail break areas ■ Turnouts before and after deviations ■ Long bridges ■ Inside long tunnels ■ Additional sites to bring about an even distribution of measurement sites along the track section Approximately 100 measurement sites were chosen along the 200 km track section from Vryheid to Richards Bay. Sites were chosen in such a way that the spacing between the stations was not more than approximately 3 km.
CALIBRATION A lifting frame developed by Van Tonder3 is used to calibrate the strain gauges that measure the longitudinal rail forces at each of the measurement stations. An example of such a frame is shown in figure 6.
18 Civil Engineering | May 2008 The lifting frame works on the received from the remote measuring basic principle that if a piece of string stations in a structured way. A unique is tensioned on both ends and then station ID is used to link the data to displaced at the centre of the string, a pre-configured measurement stations specific force is needed to displace it. on the database. Currently, datasets are The higher the tension in the string, the received from the 100 measuring sta- higher the force needed to displace it at tions at an interval of three minutes. its centre. The frame is pre-calibrated The main purpose of the calcula- for each type of rail it will be used on. tion module is to convert the strain The track fastenings are loosened measurements to forces and to calculate over a distance of 20 m after which the the stress free temperature (Tneutral) at lifting frame is used to lift the rail a each specific measuring station. When distance of 70 mm. The force required longitudinal strain in the rail is meas- to do this is then measured accurately ured, Tneutral can be calculated with the and used to calculate the stress-free following equation:4
(neutral) rail temperature. The theory Tneutral = Tactual+ used implies that the frame can only be In which: used when the rail is in tension. ε = the measured longitudinal strain This section completes the descrip- in the rail tion, installation and calibration of the The rail crown and side wear, which WILMA system. The next section de- affect the cross-sectional area of the scribes the software that was developed rail, are also taken into account when to receive and interpret the data in an longitudinal rail forces are calculated. intelligent manner. The forecasting module estimates the expected rail temperature from SOFTWARE forecasted air temperatures. In South Infrastructure condition monitoring Africa, the following relationship has software (iCOMS) was developed for been determined after extensive moni- the following purposes: toring:4 ■ To configure a group of measuring Y = 1,64X −8 stations in such a way that they will In which: function as a system with specific Y = rail temperature (˚C) infrastructure condition monitoring X = air temperature (˚C) characteristics As these equations do not make pro- ■ To receive data sent from GPRS mo- vision for factors such as wind and dems at remote measuring stations shadow, the following relationships and to store the different measure- were established for the maximum and ments in a database minimum expected rail temperatures:3 ■ To visually present the data in a Ymax = Xmax + 23
simple format Ymin = Xmin + 23 ■ To carry out elementary mathemat- Using the above equations, it is possible ical functions to the data to predict which of the measurement ■ To do trending and forecasting anal- stations might trigger the specified yses on the accumulated data alarm limits in the near future. ■ To present the results of the analyses in The viewer can be installed on any such a way that intelligent maintenance PC connected to the Transnet Freight decisions can be deduced from it Rail intranet to view real time as well as ■ To apply specific maintenance and historic data of the different measuring alarm conditions to the data and stations. It is envisaged that, once fully results The report generation module gen- operational, the system will be ■ To generate user-defined reports on erates three types of monthly reports infrastructure condition from the accumulated data and the widely used within Transnet Freight The software comprises four com- condition of the system. These reports Rail by infrastructure managers, ponents, namely a database module, include the following information: calculation and modelling (trending maintenance managers, the Coalline Condition report and forecasting) modules, a graphical Operations Centre, production presentation module with maintenance ■ Stations online and alarm conditions (the viewer) and a ■ Stations in normal/safe condition managers and finally by technology ■ report generation module. Stations requiring maintenance management for further research The database module stores all data ■ Stations with alarm conditions
Civil Engineering | May 2008 19 Maintenance report range within a specific geographical ■ Specialised removal and replacement ■ Monthly maintenance advisor area is the rail temperature range at of instrumentation for certain main- ■ Suggested sections for de-stressing which forces in CWR should not cause tenance operations, that is, ballast ■ Suggested temperature ranges buckling in extreme heat or a rail break screening and rail replacement ■ Guidelines for de-stressing during extreme cold weather. ■ Like most other wayside equipment, Figure 8 shows an example of the the system is prone to damage by Historical data report longitudinal rail force and the rail and lightning ■ Monthly longitudinal rail force and stress free rail temperature data respec- temperature plots tively as presented in the iCOMS detail INFLUENCE ON TRACK MAINTENANCE ■ Monthly maintenance requirements display. Although the system was designed to ■ Monthly alarm conditions The upper and lower alarm limits have a minimal impact on track main- ■ Overall system health are configured in such a way that the tenance, special attention is required following maintenance actions and train depending on the type of maintenance SYSTEM INTEGRATION alarms are generated: that is carried out in close proximity to Figure 7 gives a schematic representa- ■ The enforcement of a speed restric- the measuring stations. tion of the WILMA system. A number tion to lower the risk of a derailment of measurement devices are config- due to rail buckling or a rail break On-track maintenance ured to form a measurement station. ■ The stopping of all trains over the In the cases of tamping and rail grinding, The measurement stations are then specific track section these actions can proceed with cau- grouped together to form the WILMA ■ De-stressing of the track when condi- tion. Extreme caution is required when system. The iCOMS software controls tions of extreme heat or cold demand ballast profiling is carried out. The rail the WILMA system (amongst other this mounted strain gauges and cabling have systems) and sends reports to Transnet ■ Offloading of ballast to increase the to be removed when ballast screening is Freight Rail’s I2CMS (Integrated lateral and longitudinal stability of carried out. The system is unaffected by Infrastructure Condition Monitoring the track the passage of geometry cars, the UMC System – under development). The (ultrasonic measuring car), grease cars I2CMS is the twin brother of Transnet ADVANTAGES AND DISADVANTAGES and other high-rail vehicles. Freight Rail’s ITCMS (Integrated Train Advantages Condition Monitoring System) which The advantages of the system can be Off-track maintenance monitors all condition aspects related to summarised as follows: All manual off-track maintenance ac- the rolling stock on the line. ■ Intelligent maintenance at the right tions close to the measuring stations Maintenance warnings and alarms time and place need to be supervised with extreme are sent to the relevant depot for action ■ Continuous CWR rail force measure- caution. In the cases of rail and sleeper while stop train alarms are sent to the ments replacement as well as the placing of CTC (Centralised Train Control) and ■ Assist in derailment prevention closure rails, prior notification is re- SOC (Satellite Operations Centre). ■ Possible rail break and rail buckling quired for the temporary removal of the It is envisaged that, once fully op- detection measuring devices and cables. erational, the system will be widely used ■ Maintenance management and cost within Transnet Freight Rail by infra- savings CONCLUSIONS structure managers, maintenance man- ■ Continuous research possibilities due The WILMA system has been de- agers, the Coalline Operations Centre, to system expandability veloped to manage CWR on a heavy production managers and finally by ■ Advantages to other maintenance haul line in South Africa. Rail force technology management for further actions (for instance tamping and and temperature are measured at a research. placing of closures) substantial number of measuring sta- ■ Better understanding of CWR and tions on a 200 km track section. These DATA PRESENTATION track behaviour measurements are remotely sent to a Longitudinal rail force (left and right), ■ Supporting data in the unfortunate central file server running software that as well as rail temperature, is measured event of a derailment stores the data, calculates useful track at each measuring station. The stress, ■ Improved track safety, reliability and parameters from it, applies alarm limits free (neutral) rail temperature is then availability to the calculated parameters and carries calculated from the field measurements. out trending and forecasting routines. Unique upper and lower alarm Disadvantages The system is a useful and elegant tool limits are defined for each measure- The disadvantages of the system can be in the world of high tech heavy haul ment station for the measured forces as summarised by the following points: and contributes to the safe and efficient well as the temperature measurements. ■ The system requires a high level of operation of a railway line. These are based on experience, the maintenance. A dedicated team has to local track conditions of the site as well maintain the supply of electricity, the Acknowledgements as the desired temperature ranges for rail bound instrumentation and the The contributions of all staff from Transnet the climatic region in which the site data acquisition system at each of the Freight Rail Technology Management are is situated. The desired temperature numerous measuring stations gratefully acknowledged. A special word of
20 Civil Engineering | May 2008 The system is a useful and elegant tool in the world of high tech heavy haul and contributes to the safe and efficient operation of a railway line
thanks is extended to the Track Technology Kiruna, Sweden, pp 579–586. staff (George Goch, Johannesburg) whose 2 Esveld, C 2001. Modern railway track. 2nd ed. enthusiasm and hard work largely contributed The Netherlands: MRT-Productions. to the success of this project. The support of 3 Van Tonder, J P A 1996. Managing con- the Coalline Infrastructure (Maintenance) staff tinuous welded rails. Master’s dissertation, has been paramount during the installation of Pretoria Technikon, Pretoria. the system. Motswedi TLC is acknowledged for 4 Lombard, P C 1978. Continuously welded the development of the system software and rails. Proceedings of the 6th Five-yearly SAICE communication modules. Conference, 5–9 June 1978, Durban.
References This article was adapted from a paper 1 Gräbe, P J, Freyer, R V and Furno, R F 2007. presented by the same authors at a conference An intelligent condition monitoring system of the International Heavy Haul Association for the management of continuously welded (IHHA) in Kiruna, Sweden, and entitled ‘An rails. Proceedings of the International Heavy intelligent condition monitoring system for the Haul Association Conference, June 2007, management of continuously welded rails
7
Systems
Measurement stations
Measurement devices
7 Schematic representation of the WILMA system 8 Example of longitudinal rail force data
8
Civil Engineering | May 2008 21 Text Leon Zaayman Plasserail [email protected]
The philosophy behind cost-efficient track maintenance
Railway is a mode of transport uneconomical as this will reduce the This article uses hypothetical competing with a number of other service life of the track and increase the examples to illustrate how the modes of transport for business which depreciation cost. is the sustenance of any business’ exist- The objective should therefore be to maintenance strategy can be ence. Whether the business receives an lower the track geometry deterioration optimised, measured over the life adequate share of the market depends rate and preserve the service life of on a number of factors of which com- the track by employing optimised of the track. The examples are petitiveness is a major contributor. maintenance strategies. supported by relatively new research In very simplified terms the cost of This article uses hypothetical transporting goods will be calculated examples to illustrate how the results by Professor Peter Veit from by adding up all the business expenses maintenance strategy can be optimised, the Technical University of Graz in such as labour, energy, maintenance, measured over the life of the track. The depreciation (the construction costs examples are supported by relatively Austria, in his paper ‘Outsourcing in divided by the functional life of the new research results by Professor Peter track maintenance’ as read at the track) and profit, and dividing that by Veit from the Technical University the total expected load to be carried per of Graz in Austria, in his paper OVG conference in September 2004 year to get to a rand per tonne rate. ‘Outsourcing in track maintenance’ As maintainers of track we control as read at the OVG conference in the maintenance and depreciation September 2004. His paper is based aspects of the calculation and can on a major project, ‘Track strategy’, by contribute towards competitiveness by the Austrian Railway since 1996 that a reduction in those costs. However, concentrated on the optimisation of studies (in Austria) have shown track maintenance. that maintenance only accounts for 17 % of the total maintenance THE EFFECT OF budget as opposed to a minimum of MAINTENANCE ON TRACK LIFE 50 % for depreciation costs. Savings Figure 1 is a schematic representation of on maintenance cost by doing less a hypothetical track deterioration curve maintenance will prove to be very and the influence of maintenance on
Civil Engineering | May 2008 23 1 track life. An increase in track roughness Hypothetical track deterioration will result in an increase in dynamic J Original as-built loads, which will accelerate the rate of A D F condition deterioration. The curve AC represents H deterioration of an asset with no main- tenance intervention. If the deteriora- K tion is left unattended, the functionality of the asset will reduce until it can no longer be used. This can be compared with a motorcar that is bought new and Threshold for min over distance travelled, deteriorates in B E G I allowable track condition and wear to a point where it condition becomes unsafe to drive. The same applies to the track. For the safe passage of traffic, the track cannot be allowed to deteriorate beyond C the threshold for minimum allowable Time/tonnage track condition. Similar to the motorcar, the deterioration rate of the track can 2 be slowed down through planned
Hypothetical track deterioration maintenance actions which are carried Too late and too little out on time. However, the original as- built functional condition cannot be B D regained by typical maintenance input (as depicted by BD) due to the wear of the track components. After maintenance input the track will continue to deteriorate (DE). Once again, as the deterioration approaches
Track condition the threshold for minimum allowable track condition, maintenance input is C required (EF) and, as before, the con- dition as achieved after the previous maintenance input cannot be regained. A This process continues with each maintenance input achieving a lower Time/tonnage track condition than before and the interval between maintenance inputs reducing exponentially. This produces 3 a new deterioration curve (curve AK) Hypothetical track deterioration which is much longer than the curve AC Initial quality without maintenance input. The life of the track has therefore been extended. This process will continue until the period between required mainte- nance inputs becomes uneconomically short (compare distance GI with BE). Complete track renewal e.g. formation rehabilitation, replacement of sleepers, rails, fastenings, ballast or any combi-
Track condition nation of these components will then be required (IJ). The whole process will repeat itself.
1 The effect of maintenance on track life 2 Track deterioration curve with inadequate Time/tonnage financial investment 3 The effect of high initial quality on track life
24 Civil Engineering | May 2008 THE EFFECT OF INADEQUATE construction standards for new lines FINANCIAL INPUT OR POOR should be aimed at achieving high ini- MAINTENANCE STRATEGIES ON tial quality of track and the subsequent TRACK LIFE maintenance input should be aimed at Track maintenance comprises a large activities which will lower the track ge- percentage of any railway’s operational ometry deterioration rate such as clean expenditure. When financial difficulty ballast, good drainage, profiled rails, is experienced, the maintenance budget lubrication, etc, which will extend the will usually be reduced first. The graph service life of the track. in figure 1 was based on the hypothesis These decisions must of course be that the necessary maintenance input taken with due consideration given to in financial terms has been allowed for. traffic density, speed and axle loads that The question arises what the case will will be carried by the track. be if the maintenance input is inade- If the above principle is applied quate – that is, both in terms of mainte- correctly, the lifecycle cost of the track nance intervention at a point below the will remain at affordable levels without maintenance threshold (too late) and/or having to undermine the service life of insufficient input (too little) to achieve the track. the highest possible condition. A few more assumptions, though Figure 2 illustrates how the dete- proven in practice, can be made. rioration curve will be much shorter ■ A system should be in place to es- than what the potential is if timeous tablish when the deterioration is ap- and sufficient maintenance was carried proaching the threshold where main- out. The life expectancy of the track tenance is required. This requires the has been drastically reduced. In addi- measuring of the track parameters tion, the input required to renew the and footplate inspections to establish track (line AB) will greatly exceed the the track information required for input that would have been required if calculated decision-making timeous and sufficient maintenance was ■ Every maintenance input should aim carried out (line CD). to reduce the deterioration rate, that is, durability of maintenance should THE EFFECT OF INITIAL be aimed for. Maximum durability QUALITY ON TRACK LIFE can be achieved if appropriate and The influence of the initial quality proven mechanised maintenance ma- of the track also needs mentioning. chinery is used. This is also aimed at Decisions made during the planning, achieving high initial quality, some- design and construction phases of the thing that is difficult to achieve with track have far-reaching consequences hand labour for expenditure later in the life of the ■ Whether or not mechanised methods track structure. The use, for example, are utilised, any track maintenance of lower standard track components, department needs a well managed, or lower standards of formation or trained and motivated labour force. drainage construction, may save The extent to which the employees’ money in construction costs, but the motivation, needs, skills, experience extra track maintenance cost and and values are properly aligned with train delay times that result from this the company’s objectives, needs, lower standard of work will consume values and norms will directly influ- these savings several times over. The ence the quality and durability of higher the initial quality of the track, track work performed the greater the quality reserve, and ■ Resources will invariably be limited the longer it will take before the next and proper planning becomes crucial The influence of the initial quality maintenance intervention becomes to utilise the resources effectively of the track also needs mentioning. necessary, as illustrated in figure 3. and economically. This can only be The Tazara line is a good example of achieved if a maintenance manage- Decisions made during the planning, how a high initial quality with well- ment system is employee design and construction phases constructed cuttings and drains allowed ■ The length of the deterioration curve a very long service life from the track will depend on how close the main- of the track have far-reaching despite limited maintenance being tenance input brings the track condi- consequences for expenditure later carried out. tion back to the level before, taking Therefore, the selection of initial into consideration the wear and tear in the life of the track structure
Civil Engineering | May 2008 25 4 in the track components. This implies that proven maintenance practices Annual cost Depreciation Operational costs Maintenance costs and maintenance strategies should be applied at all times
100 RESEARCH THAT SUPPORTS THE 80 ABOVE HYPOTHETICAL EXAMPLES
60 The paper presented by Professor Peter Veit (‘Outsourcing in track mainte- 40 Normalised
annual cost (%) nance’) provides some of the vital tech- 20 nical and economical correlations of the
0 track which supports the hypothetical 5 0 1 0 0 1 5 0 example used above. The paper was
Tra c (number of trains per day – both directions) based on the Austrian project which concentrates on the optimisation of track maintenance by implementing strategies that take the total cost of the 5 track into account from initial con- struction to the next complete renewal. An understanding of the research results should be carefully considered by us in South Africa in an effort to op- Q 0 timise our maintenance strategies. The Overall behaviour following are extracts from the paper by pattern at Threshold 2 Professor Veit (including figures 4–6).
Threshold 2 The evaluations and analysis of the Track Strategy project highlighted a Overall behaviour pattern at Threshold 1 number of facts (see figure 4) including : Threshold 1 ■ When the traffic decreases, the life-
Q (ADA) Time cycle costs for the track also decrease ■ The total lifecycle cost comprises depreciation (the construction costs divided by the functional life of the track in years / tonnage / number of 6 axle passes), running or operational costs and maintenance costs ■ The additional operational costs as a result of maintenance (impact on Decreasing traffic, occupations, etc) can exceed threshold the maintenance costs The main conclusion of the analysis was that the optimisation of track costs, that is, reduction of the lifecycle costs, is only possible through a reduction of de- preciation through the extension of the service life of the track. On the other Track condition Constant threshold hand, the analysis showed that there is little room for savings on maintenance costs since when maintenance is re- duced, the life expectancy of the track will decrease sharply which will in- crease the depreciation costs. The result is very uneconomical, which is likely to
Increasing 4 threshold Summary of track lifecycle costs against traffic 5 Summary of the effect of maintenance due to threshold 6 The effect of the various Time/tonnage thresholds on lifecycle
26 Civil Engineering | May 2008 have the opposite effect – an increase in With a constant threshold, maintenance intervention will always take place lifecycle cost. The analysis was there- when the track condition has reached a predetermined level, irrespective of the fore summarised as follows: adequate maintenance from the start will lead to age of the track such as the coal line example. From the hypothetical figures a long service life, optimising the track provided, it can be seen that to maintain this quality level, the period between economics. The article also addressed the effect interventions will become shorter due to the wear of the track components that maintenance has on the lifecycle of the track. It refers to actual results which are almost identical to the hy- The research analysis of the Austrian a crucial role in making the railway pothetical example used in figure 1. project however provides a different competitive through the application Quality improvements are said to be approach. Starting from the bottom of scientific maintenance strategies dependent on, inter alia, the threshold of figure 6: an increasing threshold and practices which extends the life of for minimum allowable track condition means that while the track is new, the the track and in so doing reduces the (see figure 5). threshold is set very low and invest- depreciation cost. This can be achieved If the threshold for maintenance ment in maintenance is limited. Initially through: intervention is set at point 1 (low the effect thereof cannot be seen. As ■ Having a long-term approach and threshold), the effect of too little main- the track ages, the threshold has to in- considering every effort in terms of tenance will be hardly noticeable at first crease due to the increasing wear of the the lifecycle cost. The worst approach but the service life can already have other track components, to maintain will be to reduce maintenance in the been reduced due to the knock-on effect a reasonable availability and track life. short term to save on costs as this will of the first track defect. For example, if However, the knock on effect referred have a detrimental long term effect the track roughness index is set to low to earlier has already taken its toll and and may very well put the railway out before tamping takes place, the rough- will negatively impact on the life of the of busines ness will cause higher dynamic loading track. This is probably not a mainte- ■ The position/value of the mainte- of the track which will cause crushing nance strategy, but rather the result of nance threshold must receive careful of the ballast, which in turn will result financial constraints or neglect. consideration. The Austrian project in fines in the ballast bed retaining With a constant threshold, main- confirms this philosophy by providing moisture, etc; eventually resulting in tenance intervention will always take evidence that if maintenance inter- damage to the permanent way mate- place when the track condition has vention takes place too late or is in- rial. When the maintenance measures reached a predetermined level, ir- adequate, the depreciation value will are set for a low quality threshold, the respective of the age of the track such increase which will make the railway evaluation showed relatively high initial as the Coalline example. From the uncompetitive improvements in quality values, how- hypothetical figures provided, it can be ■ Implementing a decreasing threshold ever, this level is not sustainable and seen that to maintain this quality level, which will see track defects and pre- the deterioration will rise. The quality the period between interventions will ventive maintenance being addressed level achieved after maintenance will be become shorter due to the wear of the early during the life of the track. This lower than if measures had been imple- track components. is especially applicable to all the new mented sooner. Intensive maintenance The most economical approach to turnouts that are currently being efforts at a later stage to extend the track maintenance was proved by the installed service life once more proved uneco- Austrians to be when money is invested Wisely planned and implemented main- nomical. in a high level of quality initially with tenance at regular intervals will extend The level at which the threshold is corresponding maintenance which leads the life of the track to remain economi- set is therefore of significant economic to a long service life, that is, economic cally viable for many years to the benefit importance. Furthermore, calculations advantages in the future. In other of economic growth of our country, to have shown that the threshold from an words, a long service life and lowest life- the benefit of the environment from an economic point of view should not be cycle cost can be expected when a high energy consumption point of view and to set at a fixed value but it should rather initial quality has been achieved during the benefit of road users through reduced be linked to the age of the track. It can construction and when the threshold traffic congestion and fatal accidents. be proven that this type of threshold for maintenance intervention is at its leads to a longer service life and is gen- highest while the track is still new. The References erally more economical. threshold is then gradually reduced to- 1 Lichtberger, B. Track maintenance strate- The general tendency by main- wards the end of the track life. gies for ballasted track – a selection. In Rail tenance managers is to maintain a Engineering International Edition, 2001(2). constant threshold for maintenance CONCLUSION 2 Course proceedings – introduction to intervention throughout the life of the In South Africa, where the railways multi-disciplinary concepts in railway engi- track. In a practical example, the track are not subsidised, they must pay out neering. University of Pretoria, Chair in Railway quality index (TQI), as measured by the of profits for their ‘road’, unlike the Engineering. track recording car, is set on 1,6 for the trucking industry which uses public- 3 Veit, P. Outsourcing in track maintenance. Coalline before tamping takes place. funded roads. As maintainers we play OVG Conference, September 2004.
Civil Engineering | May 2008 27 Gautrain sleeper delivery on track
Infraset Infrastructure Products is on schedule with the supply of Gautrain’s concrete sleepers to the Gautrain Sleeper Joint Venture. These include B70 sleepers for the ballast track as well as sleepers for the 1 in 9 turn- outs. Moreover, all the sleepers for the Marlboro depot have been delivered. Infraset, which won the contract to supply both track and turnout sleepers against stiff international competition, is supplying a total of 190 000 sleepers man- ufactured to the Bombela Consortium’s requirements. In addition to the 1 in 9 turnout and B70 sleepers already supplied, they will include 1 in 12 and 1 in 18,5 turnout sleepers. The standard gauge 2,5 m B70, which is designed for high-speed lines, is used widely in Europe, where over 40 million have been installed to date. Kobus Burger, general manager railway products at Infraset, says the turnout sleepers are also being manu- factured to European specifications and standards for high-speed passenger lines. ‘We received the coordinates for the turnout sleepers from VAE South Africa The first 1 in 9 turnout set manufactured by VAE South Africa for the Gautrain Rapid Rail Link project during September last year and delivered shortly before delivery to the Gautrain Sleeper Joint Venture. The set was assembled using highly the initial sets during the first week of specialised concrete sleepers manufactured to a tolerance of 0,25 mm by Infraset Infrastructure Products December. VAE South Africa sets ex- tremely high standards and specified that Infraset, which won the contract to supply both track and turnout sleepers the sleepers be manufactured to toler- against stiff international competition, is supplying a total of 190 000 sleepers ances of 0,25 mm.’ Burger observed that two notable manufactured to the Bombela Consortium’s requirements. In addition to the milestones are integral to the railway line 1 in 9 turnout and B70 sleepers already supplied, they will include 1 in 12 and on this project. ‘It is the first time that swingnose 1 in 18,5 turnout sleepers crossings have been used on 1 in 9 turn- outs in South Africa and it is also the first time that rail cant is being deployed on 1 in 12 and 1 in 18,5 turnouts.’
Civil Engineering | May 2008 29 Month end 30 April 2008 Gautrain construction update
SOUTHERN SECTION Within the station box, waler beams and struts have been Underground section installed to provide temporary lateral support to the perimeter Park Station walls during station box excavation. Excavation of the single-track rail tunnel towards Emergency Shaft 2 in Houghton has reached approximately 310 m from the Emergency Shaft 1 (Hillbrow) tunnel portal. Construction of the underground station box and The single-track rail tunnel between Park Station and Sandton multi-storey parkade foundation is making good progress. Station will feature seven emergency access shafts. These shafts will provide emergency services personnel access to the tun- 1 nels below. At the bases of these shafts there will be safe havens where passengers can gather in case of an emergency. The land required for Emergency Shaft 1 in Hillbrow is in the process of being expropriated. Site establishment and shaft exca- vation will start once this process has been completed.
Emergency Shaft 2 (The Wilds, Houghton) At Shaft E2, shaft lining was completed to the 38 m depth above the cavern and grouting ahead of the cavern excavation was in progress. Once this cavern is complete, an adit linking the bottom of the shaft to the tunnel alignment will be excavated, from where two rail tunnel sections will be excavated. The one tunnel will head south towards Park Station, while the other 2 tunnel will head north towards Rosebank Station.
Emergency Shaft 3 (Riviera) Construction of this shaft will start soon. The construction site has been hoarded and site establishment has commenced.
Emergency Shaft 4 (Houghton) Excavation of this shaft has been completed to its 14,3 m final depth.
1 Aerial view of Park Station 2 Placing of the longitudinal braces for the station box, Park Station
Civil Engineering | May 2008 31 Rosebank Station Tunnel lining segments are manufactured at an offsite facility The giant Tunnel Boring Machine (TBM) has already installed and are delivered to site. approximately 460 tunnel lining segments rings in the single- Excavation of the underground station box and its base slab track rail tunnel being bored towards Emergency Shaft E2. This is completed. Construction of the external walls within the sta- equates to a distance of almost 690 m of tunnel bored below tion box is in progress. Excavation of the single-track rail tunnel Oxford Road. towards Emergency Shaft 5 has reached 250 m. This moving factory uses latest international technology to bore a 3 km section of the tunnel from Rosebank Station south- Emergency Shaft 5 (Dunkeld, Rosebank) wards. The TBM has been purpose built to deal with the difficult Tunnelling southwards towards Sandton Station – the only geological conditions along this section of the route. The re- section of tunnelling being excavated from this shaft – has mainder of the single-track rail tunnel towards Park Station will progressed to approximately 315 m. Excavation of the safe haven be excavated using conventional drilling and blasting methods. chamber is progressing simultaneously. The TBM, named Imbokodo, installs precast concrete tunnel A head house structure is visible above the shaft, which lining segments behind it as it moves forward. It leaves behind houses the overhead gantry crane. It is used for hoisting exca- a watertight and smooth lining to the 6,8 m diameter tunnel. vated rock and lowering and lifting materials and equipment.
3 4
6 5
7 8
32 Civil Engineering | May 2008 The crane is clad with sound absorbing panels to limit noise cre- final lining is being applied to the tunnel walls. Construction of ated by construction work. This is a temporary structure, which the floor slab to support the railway tracks is in progress. Concrete will be removed once tunnelling operations are completed. walkways are being installed and construction of the dividing wall separating the two sets of tracks is in progress. Construction of the Sandton Station cut and cover structure adjoining the portal continued. Construction of the cavern for the underground station is in The portal at Marlboro is the point where the tunnel ‘day- progress. Excavation of the three level parking basement is lights’. It separates the underground and surface sections of the complete and construction of the parkade foundations has com- route. menced. Excavation of caverns in both directions from the 45 m deep Surface alignment shaft at the southern end of the station continued, with the Marlboro Station and N3 Underpass single-track rail tunnel cavern towards the south having pro- A continuous longspan elevated rail bridge is called a viaduct. gressed to approximately 45 m. Several viaducts are being built to cross rivers and roads on Gautrain’s route. The precast concrete deck segments for these Mushroom Farm Park viaducts are being manufactured at the precast yard. Two sets of tunnels are being excavated towards Sandton. The At Viaducts 1a and 11, which cross the Jukskei River and single-track tunnel has reached Sandton Station and remained East Bank Road in Alexander, the southern abutments – the last at 472 m, while the double tunnel towards Sandton continued, elements of substructure remaining – approached completion, reaching approximately 280 m by month end. ahead of the arrival of launching girder T1, which has completed The double tunnel towards Marlboro Portal reached approxi- mately 650 m. Later this year, the tunnel being excavated from 3 Aerial view of Rosebank Station Mushroom Farm Park will meet with the tunnel being excavated 4 Inside of the TBM tunnel looking back to the entrance/shaft, Rosebank Station from Marlboro Portal to form one continuous tunnel. 5 Reinforced steel cage for the segment mould Mushroom Farm Park is a temporary shaft used to provide 6 TBM after the sides of the moulds have been removed the segment access for tunnel construction. is vertically removed out of the mould with a vacuum-lifting device The community park will be fully reinstated once construc- 7 The tunnel towards Sandton tion operations are complete. 8 Emergency Shaft 5 9 Aerial view of Sandton Station Marlboro Portal 10 Excavation of the shaft Excavation of the double-track tunnel towards Mushroom Farm 11 Formwork, Marlboro Portal Park approached 1 870 m from the portal. Inside the tunnel, the 12 Partition wall of the tunnel at 108 m
9 10
11 12
Civil Engineering | May 2008 33 13 14
15 16
its work at Viaduct 3. Once the launching girder is assembled, jacent to the train depot. This facility uses high-tech rail-welding deck erection will commence. methods which eliminate the need for jointed gaps between rail Earthworks, retaining walls and associated drainage struc- lengths. The laying of trackwork for the stabling sidings at the tures are in progress between the Marlboro Portal and the N3 train depot has commenced. Crossing, including in the area of the Marlboro Station, where The precast yard – also temporarily located at the depot – is station construction has now started. equipped with twin concrete batching plants and several over- Construction of a series of underpasses, where the two head gantries and tower cranes that are required to manufacture pairs of railway lines cross below the N3 highway alongside the a variety of precast concrete elements. These include viaduct Marlboro Road bridge, continues. segments, bridge beams and parapets, tunnel walkway sections and noise barriers. From here, precast elements are transported NORTHERN SECTION to the various construction sites as needed. It is currently the (DEPOT TO HATFIELD STATION) largest precast facility in Africa. Depot, precast yard and rail welding facility Midrand area Construction of this section of the route between the N3 Construction is now well under way in the vicinity of Midrand crossing and the depot is well advanced. Station and continuing towards Centurion. At Viaduct 2, over Modderfontein Spruit, Mbeam erection Construction of Viaduct 3 over Allandale Road is making was completed, side panel installation is well advanced and good progress. All thirteen of the deck spans have now been casting of deck slabs on top of the Mbeams is in progress. erected and this launching girder will now be dismantled and At the train depot, Gautrain’s 24 train sets will be main- transported to Viaducts 1a and 11 at Marlboro. tained, serviced cleaned, and securely stabled overnight. The Deck segments are erected using massive purposebuilt adjacent bus depot will perform a similar function for Gautrain’s launching girders. These girders are launched across the sup- dedicated fleet of 150 luxury buses. Construction of these facili- porting piers to rapidly assemble the precast deck segments. ties is well advanced, with the bus depot administration building Segments are then glued and stressed together to form the deck already complete and the train depot offices and maintenance spans. This international bridge deck assembly method enables workshops targeted for completion within the next few months. construction to proceed with minimal disruption to existing in- The welding of rails into 216 m long lengths has commenced frastructure and traffic below. There are two of these underslung at the temporary flash butt welding yard that has been set up ad- launching girders deployed on the project.
34 Civil Engineering | May 2008 17 18
At Viaduct 4, which crosses Rietspruit and Olifantsfontein 19 Road South, construction of the supporting piers and abutments is in progress. Construction of a number of smaller road-over-rail bridges in this area continues, including at Ridge Road, West Road, New Road and George Road.
Centurion area Viaduct 5 carries the elevated alignment through Centurion. It stretches over the John Vorster Interchange crossing the N1 in the south and then continues through Centurion to the Jean Avenue Interchange crossing the Ben Schoeman highway in the north. The sinking of deep foundation shafts for Viaduct 5 at both of these interchanges continues, and construction of the supporting piers is in progress at the Jean Avenue section. Several temporary steel pedestrian bridges have been erected 20 over the N14 highway at the Jean Avenue Interchange and across the N1 at John Vorster Interchange to provide construction workers safe access across these busy highways. Within Centurion itself, foundation construction – com- prising excavation, preloading, grouting and piling – is under way at many of the viaduct pier locations, including those which will support the elevated platforms of Centurion Station. This station will be situated on the northern side of West Street close to Centurion Lake. Utility diversions throughout the Centurion area are ongoing.
Pretoria area Construction of an underpass where the Gautrain rail track will cross underneath the Ben Schoeman to the south of Salvokop is in progress. 13 Aerial view of the N3 Crossing Piling for the pier foundations has started at Viaduct 7, which 14 Construction of the underpass will cross Nelson Mandela Boulevard at the entrance to the city. 15 Aerial view of Viaduct 3 over Allandale Road At Pretoria Station, the existing staff parking area has now 16 Viaduct 3 been vacated to enablemconstruction of the Gautrain Station to 17 Aerial view of Viaduct 5, Centurion proceed. Hoarding has been erected around the construction 18 A series of temporary steel pedestrian bridges have been site. erected over the N14 highway at the Jean Avenue Interchange and across the N1 at John Vorster Interchange to provide Hatfield area construction workers safe access across these busy highways Between Pretoria and Hatfield a number of bridges crossing the 19 Aerial view of Pretoria Station existing railway line require to be widened to accommodate the 20 Vantage point overlooking the existing Pretoria Station adjacent Gautrain tracks. and the new site for the Gautrain Pretoria Station
Civil Engineering | May 2008 35 21 A short distance to the east, foundation and abutment construction continued at Viaduct 14, which will span Zuurfontein Road and the adjacent existing railway line
21 The launching girder at Viaduct 13 22 Viaduct 13 23 Aerial view of Viaduct 15 towards airport 24 Viaduct 15 pier construction at Rhodesfield
Abutment construction for the widening of the Lynnwood Road bridge continued, as did foundation work and piling at the Ridge Road bridge. This bridge will replace the existing bridge at Willow Road, which is to be demolished. Piling at the new 22 Grosvenor Road bridge next to Hatfield Station and piling for the extension of Cilliers Street bridge commenced during April. At Hatfield Station, piling for the parkade structure was in progress and construction of the base for the retaining wall along the adjacent SARCC alignment diversion got under way.
EAST-WEST AIRPORT LINK Airport Link (Marlboro Station to O R Tambo International Airport) Deck erection at Viaduct 13 over Centenary Way in Modderfontein, using launching girder T2, is approaching com- pletion. A short distance to the east, foundation and abutment con- struction continued at Viaduct 14, which will span Zuurfontein Road and the adjacent existing railway line. Several other bridges and culverts are also currently being 23 built along this section of the route.
O R Tambo International Airport Station By far the longest viaduct on the east–west section of the route is the 1,5 km long Viaduct 15, which will carry the double-track railway line over the R21/R24 road network to the elevated O R Tambo International Airport Station. Viaduct foundations have been completed and construction of the supporting piers is well advanced. Construction of the station concourse is in progress and is visible above the elevated dropoff road. This is immediately -ad jacent to the new Central Terminal Building which is currently under construction at the airport.
24 OVERALL PROGRESS Construction started at the end of September 2006. Gautrain will be completed in two phases: ■ The first phase has a duration of 45 months. It includes the network between O R Tambo International Airport and Sandton and includes the stations at O R Tambo, Rhodesfield, Marlboro and Sandton, together with the depot and opera- tions control centre located near Allandale Road in Midrand ■ The second phase, being constructed concurrently, will be completed in 54 months, towards 2011. It includes the re- mainder of the rail network and stations linking Sandton to Park Station in Johannesburg and the route from Midrand to Hatfield
36 Civil Engineering | May 2008 Giant tunnel borer to be dismantled when reaching the end of the tunnel
■ Thrust jacks ■ Articulation cylinder ■ Steering cylinder ■ Rotary coupling ■ Main drive The 6,8 m diameter cutting wheel, which houses 48 cutters, will be dismantled. The cutting wheel will have to be scrapped but the hubs of the cutters can be reused. The wheel is used for boring a 6,8 m diameter tunnel for a single-track rail line. As soon as a 1,5 m length of tunnel has been bored, a ring of pre-cast concrete tunnel lining segments is erected behind the cutter head. It leaves behind a It will take three months to dis- When it reaches its final destination, watertight and smooth lining. However, mantle and remove Gautrain’s giant 325 t dismantling of the TBM will take place the diameter of the lined tunnel is too tunnel-boring machine (TBM) and its in phases between March and May 2009. small for the cutting wheel to be taken out 560 t of backup equipment after it has First the 145 m long back-up system com- of the completed tunnel in a single piece. completed its 3 km drive underneath prising 13 gantry trailers will be removed. Therefore, the cutting wheel needs to be Oxford Road and onto Killarney. A diesel-powered locomotive with a 25 t dismantled before being transported out This stretch of tunnelling started at pulling capacity will tow the trailers of the tunnel. Rosebank Station in January 2008. The out of the 3 km tunnel back towards The 12 m outer steel skin of the front- TBM will finally come to a halt just short Rosebank Station where the TBM started. end of the machine will remain where it of Emergency Shaft 2, situated at The is, in the tunnel. As it will be where the Wilds in Houghton, early in 2009. TBM LARGE: NOT THIS ONE TBM comes to a halt, this short section The custom-designed mixed face When the trailers have been removed, of the tunnel is bigger than usual as it earth pressure balance shield TBM is dismantling of the front end of the ma- will not have been lined with concrete designed to cope with the challenging chine (the main body) and cutter head can segments. The exposed steel skin over geology south of Rosebank. The tunnel start inside the tunnel. The dismantled this short section will be covered with borer is encountering complex conditions components and all the electric motors shotcrete to match the internal diameter with a high water table passing through will also be taken out of the tunnel for of the precast concrete lining. differing ground consisting of differing reconditioning and use on other tunnel- The remainder of the 15 km tunnel degrees of hard rock, sand and soft soil. ling projects. These include: between Johannesburg Park Station and The TBM was built over a 12-month ■ The segment erector Marlboro Portal will be excavated using period in Germany at a cost of R300 mil- ■ Screw conveyor conventional drilling and blasting, as is lion and was shipped to South Africa in ■ Material locks done on the mines. the last quarter of last year. ■ Man locks Tunnel borers are used on many
38 Civil Engineering | May 2008 The custom-designed mixed face earth pressure balance shield TBM is designed to cope with the challenging geology south of Rosebank. The tunnel borer is encountering complex conditions with a high water table passing through differing ground consisting of differing degrees of hard rock, sand and soft soil Giant tunnel borer to be dismantled when reaching the end of the tunnel
projects around the world. Urban tunnel- grouting which are carried on the gantry struction site. ling requires that the ground surface is trailers. The extension of the conveyor The cutter head is driven by seven left as undisturbed as possible to protect belts which remove the excavated ground motors and has 150 drag teeth for the underground municipal services and to the access pit however does not delay soft ground mounted on it. It also has 40 nearby buildings. This is facilitated by the process. Maintenance of or replace- single-disk cutters and four twin-disk the use of TBMs which generally disturb ment of the cutters can be done from cutters used for hard rock. The electric the surrounding ground less than drilling behind the cutter head. Access to do power rating of the cutting wheel is and blasting does. Another advantage of this is via an airlock, as the cutter wheel 2 450 kW. TBM technology is its ability to produce a chamber has to be pressurised when the The total thrust that the machine can smooth tunnel wall. machine is passing through water bearing develop against the ground is advances at ground. a thrust of 4 000 t. GOOD PROGRESS ON In order to transport the necessary THE TBM’S MAIDEN VOYAGE materials and supplies to the TBM as it By the end of February, Gautrain’s By the end of February, Gautrain’s TBM bores its way further along the tunnel, TBM had successfully excavated had successfully excavated 100 m on its service rails are laid behind it inside the maiden voyage, which started in January. tunnel. A man rider is also used to trans- 100 m on its maiden voyage, which The TBM is progressing at about 9 m a port TBM workers in an out of the tunnel. started in January. The TBM is day. When this moving factory is running The heavy precast concrete segments, to full capacity, it installs precast concrete which weigh 3,92 t each, are transported progressing at about 9 m a day. tunnel lining rings at a rate of 12 per day. on flat cars drawn by a diesel locomotive. When this moving factory is running Each ring is 1,5 m wide and comprises six The TBM is directed or driven by interlocking segments. A standard seg- a pilot (or driver) who sits in a control to full capacity, it installs precast ment weighs 3,92 t. cabin surrounded by an array of com- concrete tunnel lining rings at a When a ring of precast lining is to puter screens. His job is facilitated by a be installed inside the bored tunnel it sophisticated electronic guidance system rate of 12 per day. Each ring is 1,5 m requires the TBM to come to a temporary which displays a target he has to follow. wide and comprises six interlocking one-hour halt. As soon as the erection It allows the pilot to steer the machine of the segments has been completed, the and to continuously monitor the actual segments. A standard segment tunnel borer moves forward while the three- dimensional position of the ma- cutting wheel excavates the next section chine in relation to the theoretical centre weighs 3,92 t of the tunnel ahead. It advances a distance line of the tunnel at any given location of 1,5 m at a time – equal to the width of along its route. the ring of precast concrete segments. Work takes place 24 hours per day. ELECTRICITY REQUIREMENTS The TBM functions on a 20 hour produc- The TBM requires a total of 3,2 MW of tion shift with a four hour maintenance power to drive the 325 t giant. A substa- break. This includes the replenishment tion dedicated to the needs of the TBM of equipment and stock such as foam or is situated at the Rosebank Station con-
Civil Engineering | May 2008 39 Exciting coastal development at Gansbaai
The Gansbaai development for water and sewerage, which is literally Special emphasis was given to storm- set along the tranquil landscape of the non-existent in the area. water drainage during the stormwater Atlantic Coast offers breathtaking views Gideon Hahn from EFG Consulting design phase. ‘Where possible, open in an unspoilt setting. This exclusive de- Engineers points out that the project pre- stormwater systems were incorporated. velopment is situated 22 km south of the sented numerous highlights. According In addition, the number of detention beautiful resort town of Hermanus in the to Gideon, the terrain is completely un- ponds will be kept to a minimum in Western Cape. developed and has a duny landscape that order to reduce maintenance needs. The exciting venture commenced two stretches for miles. Fynbos and other Grass block channels will also be pro- years ago and entailed the design of some natural vegetation also grow freely and vided to take run-off from the roads to 1 000 erven, a retirement village and a placed additional pressure on the team to the detention facilities,’ explains Hahn. neighbourhood shopping centre. It has a uphold the principles of environmental Gideon is an avid Civil Designer and total project size of around 110 ha. conservation and restoration. In order AllyCAD user and is considered to be EFG Consulting Engineers is respon- to assess the feasibility of the project, a an expert in the software. He uses the sible for the project management as well preliminary design was carried out that design packages for the compilation of all as the design of all the infrastructure included the planning and sizing of in- his drawings and is skilled in the prepa- services. These include the bulk services ternal as well as bulk services. ration of survey plans and the generation
Civil Engineering | May 2008 43 of Digital Terrain Models. works transported by tanker. The treat- During the project’s execution, there ment plant currently has an operating were many stipulations. One of these capacity of 0,3 Mℓ per day, but as a me- included traffic calming during the road dium-term interim measure, the existing design. This meant that measures had to plant is currently being upgraded to be designed to discourage speeding and 1,0 Mℓ capacity and will have sufficient rat running. Raised intersections and treatment capacity for the proposed the use of block paving were among the developments in the area. ‘The design traffic calming measures employed. and planning of the new pump stations According to Gideon, the site cur- and rising main to the existing works rently has a single gravel access road has therefore commenced in earnest,’ which will be replaced by a new access explains Gideon. road from the trunk road once the con- ‘The environmental impact as- struction of the development commences. sessment process is still continuing During the execution of the project, EFG and we hope to get approval from the Engineers set about to undertake a traffic Department of Environmental Affairs impact assessment study to assist with the and Development Planning shortly for geometric design. An important stipula- the new works on the proposed site. The tion throughout the process was that spe- project has been divided into four phases cial attention be given to environmental and is likely to be completed in the next conservation and the restoration impacts four to five years,’ he says. of the construction process. Future developments in this coastal The greater Gansbaai area is cur- region include the compilation of a sewer rently served by a wastewater treatment master plan for the greater Gansbaai area. plant near the municipal offices some This master plan will, amongst others, 4 km from the proposed development identify a site for a new treatment works as with sewerage flow from the area to the well as a detailed reticulation network.
44 Civil Engineering | May 2008 New high-tech crane set to double loading capacity
Transnet Port Terminals’ Richards Bay of 51 m. Its handling efficiency is boosted by a multipurpose terminal team received a welcome container spreader able to lift 20 containers an injection into its crane fleet with the arrival of hour if required, as well as a four-rope feature components of a brand new R38 million Liebherr for versatility and the ability to operate a ‘grab’ LHM500 mobile harbour crane on board the facility if required. The crane is also able to handle Beluga Projects vessel earlier this month. substantial lifts and considerable distance from The equipment, weighing approximately its centre. 500 t, is the first crane to be purchased by the The crane components were offloaded from terminal in just over a decade. It boasts a lifting the Beluga Projects vessel on the afternoon of capacity of 140 t – and will initially be used to arrival and partly assembled at the quayside over proximately 250 m to its final destination at the speed up the terminal’s neobulk handling opera- the following days using a 30-year-old Gottwaldt terminal where assembly would be completed. tions to 20 moves per hour. Neobulk cargo refers crane which had previously been used at The R38 million crane investment forms part to over-sized, single commodity cargo which is Richards Bay harbour to position dolosse during of Transnet Port Terminals’ hefty R300 million transported in skips rather than on a conveyor initial construction of the pier. The Gottwaldt capital expenditure programme in Richards Bay belt. Current cranes in use at the terminal are only would then be transferred to Transnet National to reinvigorate capacity and performance at the able to complete eight to ten crane moves per Ports Authority while the terminal’s 11-year-old city’s multipurpose terminal over the next few hour of 20 t. Reggiane crane will be refurbished as it has years. In total, Transnet Ltd plans to spend R28 The Liebherr LHM 500 crane offers flexibility reached its mid-life cycle. billion on port-related projects over the next five in its movement with its ability to swing verti- Once offloaded and partly assembled, years to meet the country’s growing sea-based cally, horizontally and diagonally up to a radius the new Liebherr crane would be driven ap- trade demands.
Civil Engineering | May 2008 45 1
on t he c over
Esor omnipresent in Johannesburg CBD regeneration
Specialist civil and geotechnical included utilising existing basement comprised multiple lengths of steel cable engineering contractor Esor Limited has retaining walls as part of the lateral drilled at 15 degrees through the piles. played a key role in regeneration projects support system, accommodating a High pressure grouting secured them into in the Johannesburg CBD, most recently variety of soil conditions, linking of two the surrounding earth and cables were for the new Absa mega office complex, the of the sites under Delvers Street, and the tensioned to between 300 kN and 750 kN, Universal Church of the Kingdom of God building and jacking of a concrete tunnel and finally secured against the surface and a property development for Zurich to connect to the third site,’ says Tebogo of the piles with a combination of steel Insurance Company (formerly SA Eagle). Modishane, Esor contracts manager. plates, anchor heads and collets. Using its expertise in lateral support, Lateral support was provided by ‘In one case, where we could not piling and tunnel jacking, Esor is close to installing 600 mm diameter auger remove the existing six metre deep base- completing its commitments at three sites drilled cast-in-situ concrete perimeter ment wall, ground anchors were secured for Absa’s R1,2 billion new office develop- piles, spaced 2,5 m apart, secured with on steel stub soldiers from universal beams ment, Towers West. rows of ground anchors. Wick drains in pairs and steel plates, spreading the load Three city blocks within the area were included, situated within arches on the wall’s surface,’ says Modishane. surrounded by Main, Troye, Anderson intermediate to the piles, to ensure ‘Fifty millimetres of gunite was then and Von Wielligh streets will house drainage of intrusive water away from the applied to the wall and below that, to the buildings up to thirteen storeys high, buildings’ basements. 11 metre deep lowest level of the new with interlinked basements providing On two sites pre-existing base- basement, we excavated back a further necessary parking facilities for more than ment walls and foundations were first 150 mm, guniting the entire surface in 3 000 Absa staff. removed prior to adding 3 m of backfill, line with that above. Ground anchors The scope of works comprised establishing a piling earth platform to were also applied here using the steel stub underground demolition, temporary lateral facilitate the drilling of perimeter piles. soldiers.’ support, structural piling, the jacking of a The backfill was subsequently excavated, The structural foundation piles were tunnel and associated bulk earthworks. in approximately 2,5 m vertical stages, auger drilled cast-in-situ cage-reinforced ‘Specific challenges on this contract and ground anchors installed. Anchors concrete piles between 750 mm and
46 Civil Engineering | May 2008 2
1 500 mm in diameter, to maximum Anglican cathedral as well as deep under- depths of 25 m. Ground conditions varied ground services, closely spaced soil nails and included shale, diabase and hard were used instead of ground anchors. quartzite. In some places piles did not ‘Regarding structural piling for penetrate and conventional foundations foundations, the presence of deeply were needed. weathered andesite with slickensided The basement interlink entailed the joints and ground water ruled out the excavation and closure to traffic of the use of conventionally drilled auger piles,’ strip of Delvers Street passing between explains Modishane. ‘Continuous flight Anderson and Marshall streets. Delvers auger [CFA] piles were considered but not Street will be reconstructed, supported favoured for economic reasons and the by a concrete slab on top of columns, and availability of plant at the time. We chose reopened to traffic at ground level. auger underslurry piles, which are rarely The concrete tunnel to link the third used in the stiff residual soils encountered site is 8,9 m wide by 2,6 m high and on the Highveld.’ 17 m long. ‘We broke away the lower The piles were installed 20 m to 25 m legs of piles already in place at that level, deep. before excavating,’ says Modishane, ‘and constructed a temporary wall, ground SA EAGLE DEVELOPMENT anchored in place, against which to jack Esor also undertook earthworks, lateral 3 the tunnel.’ support and piling for a property devel- opment for Zurich Insurance Company CATHEDRAL (formerly SA Eagle) in the Ferreirasdorp Underground work for the new Universal area, completing this extremely fast track Church of the Kingdom of God (UCKG) project within three months. has been completed. The cathedral will The site is situated between Miriam be situated within an 8 m deep basement, Makeba, Marshall, Margaret Mncingana with an above-ground structure of seven and Main streets, just west of the storeys. Magistrate’s Courts, and the project is The site is in the heart of the northern recognised as the first new commercial CBD and challenges included the prox- development of significance in this area in imity of Saint Mary’s Cathedral and other a long while. sensitive sites, underground services and a Some of the challenges included the deeply weathered soil profile necessitating need to relocate stormwater drains and the use of underslurry piling, a rare solu- plugging a water ring main, the unex- tion in Gauteng. pected presence of water in one portion Esor was responsible for demolitions of the site, and handling delays caused by 1 Lateral support and piling under way on to the existing basement, earthworks, the metal and engineering industry strike a property development for Zurich Insurance lateral support and piling. Perimeter piles that took place at the beginning of the Company (formerly SA Eagle) west of the were not required and lateral support was contract. Magistrate’s Courts installed on three sides only, the western Soils included a diabase dyke on the 2 Part of the underslurry piling process, end being hard up against existing build- western side as well as shale, and few showing the bentonite in the hole, with air-lifting ings to the full 8 m depth required. problems were experienced in reaching of material from the bottom ‘The basement and foundations of target piling depths. Auger drilled cast- 3 A view of the completed tunnel the previous building were demolished in-situ perimeter piles were installed, and removed. As it housed a basement of prior to carrying out excavations to jobs and that his company has been able around four metres depth, the existing depths of between 7,5 m and 18 m. to play its part in the regeneration of the perimeter walls were not removed but Lateral support was provided by means Johannesburg CBD. ‘It’s satisfying to be were anchored using soil nails rather of ground anchors. Up to five rows of part of the resurgence of the CBD, which than ground anchors. Below the level of anchors were necessary at certain parts has so much history linked to it.’ existing walls, down to the full new base- of the site. He adds that the spectrum of Esor’s ment depth of eight metres, a 100 mm For the structural foundations, 124 work in the Johannesburg CBD under- thick layer of gunite was applied,’ says No. auger cast-in-situ piles varying in scores the company’s positioning as a ‘one- Modishane. diameter from 600 mm to 1 200 mm stop geotechnical shop’ whose offerings On the northern and southern sides were installed. include piling, lateral support, diaphragm of these lower surfaces, steel stub soldiers walling, underpinning, structural shot- from universal beams in pairs and plates ONE-STOP SHOP creting, grouting, shaft sinking, percussion were used to provide lateral support, Esor CEO Bernie Krone says that he is drilling, dewatering, water wells, marine secured by means of ground anchors. On pleased that his teams have shown excel- works, bridge footings, bridges and other the eastern side, given the presence of the lent performance on these challenging specialist engineering works.
Civil Engineering | May 2008 47 Text Lorraine Fourie [email protected]
people Trailblazer in geotechnics
He has been labelled idiosyncratic, demanding, impatient, at times downright bloody-minded – exacting qualities that spring from an imaginative and inquisitive mind tirelessly searching for practical solutions to engineering problems. But he is also known as a thorough gentleman, courteous and fair, a friend and confidante who takes time to listen and who cares deeply about humankind. Throughout Dr Ross Parry-Davies’life, his muse has been his wife, Renée, who has shared his every success and setback. Lorraine Fourie met the couple at their home in Hout Bay in the Cape, where, on observing their energetic lifestyle, one hesitates to say that they live in retirement
GUTSY FROM THE START ment he was rewarded with ‘four of the best’ and had to cool R P-D showed a keen interest in science from a very young age. his bum in a basin of cold water. Growing up in Queenstown, he remembers setting up his own The premature death of his father, who was the headmaster ‘laboratory’ in an old stable. at Queens College, left the 15-year-old R P-D the male head of ‘Once, I made my own Bunsen burner by installing a tube the family. Money was tight and he changed his career plans through the lid of a Lyles Golden Syrup tin, half-filling it with from a six-year medical course to a four-year civil engineering methylated spirits, pressurising the tin with a bicycle pump and course. Even so, university fees were not cheap and R P-D set lighting the jet of meths emerging from the end of the tube.’ his sights on winning the Sir Abe Bailey Bursary for the best Needless to say, he lost all his eyelashes and eyebrows in the matric results in the Border area. This he achieved, giving up resulting explosion. all sport activities for the last semester of school to concentrate This was nothing compared to the day that he built a on Latin, which he considered his Achilles heel. He started his cannon with a ½-inch barrel, charged it with gunpowder and BSc Civil Engineering studies at the University of Cape Town in match heads, and stuffed lead shot down the barrel as the 1942 and was deeply disappointed at failing his medical when projectiles. He aimed for the top of his father’s garage door he wanted to join the army at the end of that year. and fired, expecting only that the wood would be peppered After graduating, R P-D joined MacNicol Construction on with tiny holes from the shot. However, it resulted in the door the Churchill pipeline, which was being built for Port Elizabeth lurching crazily and falling to the ground. For this experi- Municipality. ‘The pipeline job was a great training ground as
48 Civil Engineering | May 2008 R P-D in 1978 as national president R P-D felt that the site, a narrow gorge, was perfect for a of the Queen’s College Old Boys Association blondin (cableway), so designed and built a home-made one that worked perfectly. it involved survey, concrete works, timbering, under and over The following two years were spent in the consulting field river crossings and excavations ranging from sand to rock with F E Kanthack & Partners (now Knight Piésold) on the to clays requiring support.’ From a shrewd Scot he learned design of the Kafue Hydroelectric Project in Northern Rhodesia about cost-accounting. ‘My family have had to put up with my (now Zambia). The couple had settled in Johannesburg with crossing Ts and dotting Is ever since.’ their first-born daughter, Janice (1953), who was soon followed by the second, Megan (1954). HARDWORKING AND METICULOUS In 1956 the Kafue project was suspended in favour of the Next step was to become site agent on the construction of a Kariba Dam. R P-D, who had used his designs for Kafue to ob- composite dam in the Zuurberg mountains in the Eastern Cape. tain his AMICE, moved back into contracting by accepting an Although still pretty green, R P-D showed his depth of thought, offer to join the Cementation Company as contracts engineer a trait for which he became renowned: ‘According to the design, on Kariba and other projects. Cementation had been sub- the left flank earth dam section was to be founded on a natural contractors on Keerom, so knew of his home-made cableway. clay blanket, resting on top of some 8 m of alluvium. This clay In his first week he was told to build a cableway within six blanket was viewed as sufficiently impervious to make it unnec- weeks, capable of carrying a two-ton truck across the Zambezi. essary to excavate a cut-off down to rock. This worried R P-D Working 36 hours non-stop, he staggered into the workshop on and he excavated trial pits downstream of the dam and pumped a Monday morning with his drawings, ready for them to start in water. ‘To my consternation I found that, at 40 000 gallons manufacturing the components. He had met the time limit per hour, I could not fill the hole as the water just seeped away with a day to spare. into the alluvial material.’ When he told MacNicol about his Still at Cementation, he applied and improved techniques concerns, the MD called a meeting. Although the inspecting for the stressed strengthening of a series of concrete dams engineer thought that the ‘youngster’ was right, construction throughout South Africa. During the construction of what went ahead according to design. In the end his fears proved is now the Dap Naudé Dam in Magoebaskloof, his design for accurate: ‘Water saturated the alluvium below the clay blanket, large-capacity steel anchor heads worked excellently in pro- which settled, shearing the contact with the concrete spillway totype and for the first twelve anchors. He was blamed when and cutting a channel 30 ft wide and 30 ft deep right down to some failed subsequently. Many years later he discovered by the rock, virtually emptying the dam. Not many civil engineers accident that the failures were because a much harder steel had can claim to have built a dam that failed, in the anticipation been used for the heads instead of the softer mild steel he had that it was likely to fail.’ Fortunately R P-D insisted on getting a specified. Cable heads, identical to his original design, were signature every day that the work had been carried out strictly later patented by a Swiss company, but it was too late for R P-D in accordance with the specs. to oppose the application. It was then that he started to court Renée Ella, a girl whom In what was a world first at the time, he applied the same he had admired ‘from afar’ since school days, and whom he technique to the provision of lateral support for a deep base- married in 1952. Soon afterwards, the newly-weds set off for ment excavation face in Port Elizabeth. ‘I had looked at a the construction site of the Keerom Dam in a gorge in the basement being excavated in Johannesburg and it was a mass Matroosberg mountains, near Worcester. The valley was so of struts and shores – very difficult to build around – and I sug- remote and isolated that it was nicknamed ‘Wegkruip’, the only gested to my MD that perhaps we could use anchors to replace means of communication to the outside world being by radio. this mess. He may have mentioned this to a consultant in Port
Civil Engineering | May 2008 49 1 2 3
In 1960 the family moved to Cape Town when fault zone about 500 m from the Camps Bay portal. ‘Of all the R P-D was appointed manager of the Cape branch tunnelling operations I had been involved with, this one was the most difficult and challenging. of Cementation. One of his first tasks was the ‘One afternoon I was met with the news that the tunnel roof construction of the Apostles water tunnel through was collapsing, the sidewalls were caving in, and the tunnelling team were knee-deep in water.’ R P-D discovered that the team, Table Mountain, which would traverse a geological who had successfully penetrated a smaller parallel fault zone, fault zone about 500 m from the Camps Bay portal. had assumed that they were through the major one. They had proceeded quickly, realising that they had reached the real fault ‘Of all the tunnelling operations I had been involved, zone only when they were 15 ft into it. By retreating about 18 with, this one was the most difficult and challenging ft and creating a sandbag bulkhead in sound rock with large pipes carrying the water through the bulkhead, then injecting a weak sand-cement grout into the collapsed zone, he got the water under control. He finally emerged after 48 hours in the Elizabeth. Shortly afterwards this consultant asked our Cape tunnel. A cement-bentonite mix was then used to form a grout Town office whether Cementation thought that anchors could curtain and the tunnel continued through this material. It took be used to support a basement excavation 15 m deep in PE. This six months to penetrate the fault, whereas tunnelling at this site concept is old hat nowadays, but in those days I was virtually had previously advanced at up to 30 ft per day. ‘The completed standing alone as everyone said it was like trying to lift oneself tunnel attracted huge interest nationally and internation- by one’s shoelaces. At a depth of 12,5 ft we put in temporary ally, also because of the “raise” at the Disa Gorge end. Nearly struts, installed the anchors, tensioned them and removed 1 500 ft was driven uphill at an inclination of 30˚, an incredibly the struts, all the while keeping our fingers crossed. The face difficult operation.’ stayed put.’ The procedure was repeated in phases all the way A technological achievement that R P-D regarded as down the entire 50 ft. R P-D tried to patent his technique, but simply a practical solution to an engineering problem was his his attorney advised him that it was simply a modification of technique of creating a gravity-type soil wall to keep boulders pre-stressing and non-patentable. He then fought off patent ap- and cobbles from falling onto De Waal Drive. ‘After creating a plications from all over the world. ‘If I had been better advised, ‘skin’ of mesh-reinforced gunite over the face above the road, I would have been a very rich man.’ I tied the skin back into the soil mass with bolts, which were By this time R P-D and Renée’s third child, David, had been anchored in cement grout and tensioned.’ He never gave this born (1956) and they happily bore the brunt of friends’ jokes technique a name, but 20 years later it was ‘invented’ in Europe about having their family in rapid ‘concussion’. R P-D was also and called soil nailing. It was taken up by GeoFranki, who refer accepted into Freemasonry. Because he had been so privileged to it as geo-nailing. in life, he felt that he would like to help those less fortunate. Vibroflotation was also unknown in South Africa at that His involvement in the movement, known for its support to the time. R P-D watched this process in the UK and realised its needy, is an indispensable part of his life. potential as a ground improvement technique, so he imported a vibroflot from Cementation UK. ‘The first major contract was Persistent and resourceful for the foundation treatment of the sugar silos in Durban, under In 1960 the family moved to Cape Town when R P-D was ap- the supervision of my colleague Duncan McColl, who, I believe, pointed manager of the Cape branch of Cementation. One of subsequently put vibroflotation on the map in South Africa.’ his first tasks was the construction of the Apostles water tunnel In 1963 R P-D was called back to Johannesburg to take con- through Table Mountain, which would traverse a geological trol of all Cementation’s geotechnical work in southern Africa.
50 Civil Engineering | May 2008 1 R P-D, on his tricycle internationally. 2 R P-D and Renée shortly before they were married He also patented what he called the ‘porcupine’ technique 3 R P-D and David Piésold camping at Van Staden’s for consolidating old goldmine workings without man-entry River Mouth when they were still cub engineers into the workings. The concept was to drill holes from the surface to intersect the stope at depth in competent rock and He and his wife were in the prime of their lives and did a great insert the ‘porcupines’ into these holes. These were made from deal of the work themselves, on the property they had acquired a central tube with ‘quills’ attached. When they were inserted, in Bryanston, teaching their children the lesson of dignity in the quills folded back. On entering the stope, they sprang out labour. RPD had more time to become involved with Queens again to create an entanglement of wires across the stope. College Old Boys’ Association and to move up the Freemason Concrete heavily ‘doped’ with fibre was then dumped through ranks, while Renée, who had a background in teaching, pri- vertical holes on to the porcupines to form a bulkhead and vately taught pupils with learning problems. the void filled with a cheap lean sand-cement-bentonite grout. His work in the use of ground anchors for lateral support When a section of Main Reef Road in Langlaagte collapsed over of basement excavations was widely applied in and around one of the old workings, the technique was used successfully Johannesburg, the major sites being the Rand Daily Mail and the road was re-opened. building at the Standard Bank Centre, the Star basement, and In 1970 R P-D resigned from Cementation to become a at least a dozen others. shareholder and executive director of Westcott & Associates. ‘In some respects I was sorry to leave, because the work I did Assertive and daring was stimulating and stretched me technically, but there were On the Star excavation, which went down to 22 m, R P-D new possibilities in the move. differed from the specialist consultant – then the doyen in Six months later he founded Ground Engineering Ltd (GEL), geotechnics in South Africa – who believed that the top two with very limited capital. He made his first grout pump from rows of anchors were sufficient. R P-D believed that anchoring pipe fittings, and the grout mixer was fabricated from a should be carried all the way to the bottom. At a depth of 44 gallon oil drum. Within two years GEL was becoming ‘a 18,3 m a huge wedge of weathered rock fell out from below thorn in the flesh’ of the big geotechnical contractors, and in the top anchors and a massive crack developed halfway across 1974 the Westcott Group accepted an offer from LTA to buy President Street. Had only the top two rows of anchors been GEL, on condition that R P-D continued to run it. As CEO of installed, the collapse would have extended to the surface, and LTA’s geotechnical arm, he widened the disciplines of GEL would have swallowed cars and pedestrians. After this, anchors to include pipejacking, guniting, horizontal collector wells, were always taken all the way down to the bottom. ground freezing and diaphragm walling. With the Trust Bank – at 31 m it was the deepest sheer The first major contract with LTA was the stressed basement in the world at the time – a different approach was strengthening of the Laing Dam for the East London adopted. He recounts the background: ‘The City Engineer tem- Municipality, where 600 tonne anchors were specified. ‘I had porarily forbade the use of anchors. He said, “Since you brought previously done anchors of 350 tonnes, but for 600 tonners this technology of ground anchoring to Johannesburg, people I was uncertain of the fixed anchorage length. I made a 36- are putting down basements where they never previously strand anchor with a 2 metre fixed anchorage length. Because thought of it; that means extra cars during peak times, and there was no jack in South Africa to test this size of anchor, I my streets just can’t cope.” Ruben Stander proposed a circular tensioned each strand individually up to 80 % of its ultimate structure, but this was rejected by the architect as a waste of strength – a total of 900 tonnes. This satisfied me that a 4 space. The concept of a ‘squashed circle’ then emerged – that metre fixed anchorage length would be OK. I once again used is, four flat arches tangential to the sides of the city block and a blondin for the job, which went like clockwork. We had only joined by four small arches at the corners. ‘However, there was one problem with the consulting engineer. He wanted to an- the risk of the flat arches buckling under the earth pressures, chor the cables in the dry.’ Remembering the early experience and Ruben and I developed the concept of creating four huge of anchoring in the dry at Dap Naudé Dam, R P-D argued that flat jacks behind the corners and pressurising these with ce- if he anchored the consultant’s way, the consultant would have ment grout to induce an inward thrust at the corners and a cor- to accept responsibility for the efficacy of the anchors, but if it responding outward thrust behind the flat arches.’ were done his way, he would accept full responsibility. ‘We an- When putting theory into practice, R P-D admits to having chored all the cables ”wet” and had not a single problem.’ had butterflies in his stomach each time they carried out the An extremely taxing project at this time was the Huguenot grouting operation. Before the job started, his friend Professor pilot tunnel. It was constructed to explore the geology of the Jere Jennings phoned him, saying: ‘Ross, don’t do it, you’ll lose proposed road tunnel between Worcester and Paarl and to your reputation completely,’ but it worked. At a conference in drive cross-cuts from the road tunnel to the pilot tunnel, so Mexico in 1969 Ralph Peck expressed interest in the technique, that in the event of a disaster in the tunnel, there would be an and at a conference in Tokyo in the early 1990s the Trust Bank escape route. The rock tunnelling on the east side gave no prob- was described as being 25 years ahead of its time. lems, but the Paarl side gave plenty. The worst possible material During this period R P-D carried out the foundation for tunnelling was encountered – completely saturated residual grouting of at least 20 dams throughout southern Africa. In granitic talus. ‘When tunnelling started on this end, we used the civil engineering field up north he became known as ‘Mr spiling, but had mud rushes. Next we tried jacking “knives” Cementation’ and was recognised as being among the top ex- ahead of the face. Again we had mud rushes. It was like trying perts on grouting technology and ground anchors locally and to dig a hole next to the sea, as the material simply liquefied and
Civil Engineering | May 2008 51 came at us.’ Grouting ahead of the face using the tube-à-man- Paarl end, we tendered with Foraki of the UK and won the chette system as an experiment for about 6 m worked perfectly, tender. Once again the job went like clockwork.’ but this pilot tunnel was only about 3 m diameter, and part of the objective of the pilot tunnel was to establish methods for INVESTIGATIVE AND PERCEPTIVE the first road tunnel, which would be 13 m in diameter. ‘We As a challenge to his engineers, R P-D put together teams con- were not confident of taking a 13 m tunnel through this mate- sisting of a young and an older engineer, and got them to look rial under cover of a grout curtain, so decided with the consult- for new geotechnical technologies that could be used in South ants that freezing offered a better solution. We built our own Africa. Duncan McColl as the senior engineer, with Bernie freezing plant with the assistance of Deilmann of Germany. We Krone the young engineer, came up with dynamic consolidation froze the water around the tunnel, creating an ice-wall within (DC), which was developed by the French Menard Group. which we could drive the tunnel, put in concrete support, and Bernie, now CEO of Esor, says: ‘What can I say about a man then allowed the ice to thaw. When the consultants called for who has had such a profound and varied influence on my life? tenders for freezing the first 160 m of the road tunnel on the Boss, mentor, colleague, and friend.’ He remembers his first impressions of R P-D: ‘I thought he was rather stiff, formal, a 4 stickler for detail, a man with his eye on the time. These at- tributes haven’t changed and he still has an eye for time as he continues to make every second of his 84 years count. But he also had patience and tolerance. I left his office one day in a huff because of some minor criticism that I couldn’t bear and slammed the door so hard that his pictures fell off the wall. I apologised later and he forgave me instead of firing me. He always gave me the benefit of his considerable experience and knowledge, and this became even more obvious after I had left GEL and he had retired to the Cape. Ross introduced me to Freemasonry and we became friends – I am often privileged to have him stay over at my home when he is in Johannesburg.’ Following the recommendation from Duncan and Bernie to look at DC, R P-D obtained an exclusive licence from Menard to use the process in South Africa. On a contract involving a 2,1 km length of road that would carry the Johannesburg Western bypass over marshy ground, they found that the underlying material did not respond to conventional DC. ‘We therefore carried out a modification of DC, called dynamic substitution. This involved pounding mine waste rock through the marsh down to competent material, and carrying the road on a similar rock mattress – also consolidated by DC spanning
5 6
52 Civil Engineering | May 2008 between the columns. We used a 40 tonne pounder dropped ately: ‘This is a Ross job.’ Basil replied that he knew it was a ‘rush’ from a height of 30 metres and built a Menard tripod to handle job. R P-D was called in and used what was considered the latest it. Certainly no pounder of this size had been used in South technology in anchoring at the time, but is not acceptable by to- Africa before, and probably hasn’t been used here since. This day’s standards. Those anchors served their purpose for 25 years was apparently the forerunner of many dynamic substitution until they were replaced during the reconstruction in 2003. jobs in other parts of the world.’ In Cape Town, on a site just behind the City Hall, Ground In 1976 tenders were called for the Drakensberg pump Engineering carried out the largest diaphragm-walling project storage hydroelectric project – at over R100 million this was a ever tackled in the country at the time. ‘Being reasonably close major project by any standard. R P-D headed up the tendering to the sea, the basement went well below the water table, and team, a joint venture between LTA and Shaft Sinkers, and they the object was to retain the sides and stop water inflow.’ won the contract. During construction R P-D was part of the Forming a joint venture with British geotechnical con- management committee of Drakon, the joint venture formed to tractor Colcrete, he became involved in the grouting ahead of carry out the construction. the Island Line, then under construction in Hong Kong. ‘The In the 1970s, while on a game drive at Londolozi, R P-D problem was that the tunnels were all below sea level, and some received a radio message from Jere Jennings to go to Zebediela very sophisticated drilling and grouting was carried out, using immediately. On arrival, Jennings took him to Magoto Dam, cements, bentonites and chemicals.’ which was piping badly. ‘The discharge was being caught in a One of R P-D’s senior representatives in Hong Kong was 44 gallon oil drum and every hour the water was decanted and Ernst Friedlaender. Ernst, who now lives in Sydney, Australia, the sediment weighed. The rate of increase was frightening. Jere commented: ‘Working for South Africa’s leading geotechnical had already alerted the police to stand by to evacuate the valley contracting company, under Ross’s inspirational guidance, at short notice if needed. He asked me how long I thought we was a dream position to be in. He was always at the forefront had before the dam failed. I estimated seven days and he thought of technology and innovation, driven by his passion for geo- four. Nobody will ever know who was right because I managed to technical contracting and carried by his ability to attract and choke the piping by grouting in four days using some very unu- inspire the people that worked for him. The words ‘can’t be sual ‘additives’. Jere and I often disagreed on geotechnical issues, done’ didn’t exist in his vocabulary. Many of the key players in but our friendship always survived. This was no exception. He our industry today have been groomed by or exposed to Ross wanted me to drill just upstream of the leak, but I had spotted a in some form or other during their career. Ross’s success can be small unusual feature in the foundation records about 50 metres measured in many ways, but possibly is best represented by the away. I drilled the first hole where I wanted to, and injected fluo- network of people around the world that have been positively rescene dye. Within 20 minutes the dye-discoloured water came influenced by him. There are not many countries in the world out at the leak. It was then a case of using every trick in the trade where someone of influence does not know Ross Parry-Davies.’ to choke the piping. “We were lucky, but as Gary Player has said, A person who remembers him well is Helen Parker, R P- ‘The more I practise, the luckier I get.” D’s former secretary. Demanding though he was – she recalls In those years he became involved with Chapman’s Peak having to retype a 55-page report five times – R P-D was the Drive. On viewing a major rockslide in 1977, Professor Tony most courteous and fair man she ever had the pleasure of Brink, who had been called down by Basil Kantey, said immedi- working with. ‘I never
4 7 8 R P-D and Renée in 1961 in front of the portal of the Apostles tunnel through Table Mountain 5 From left: Mickey Burke, the geologist Pulic, Renée, and Professor Jere Jennings (back to camera) with his two daughters inside Pulic Cave, a sinkhole in the course of development. It is probably the only time that people have been able to enter such a cavern 6 Cartoon of R P-D sitting on bags on mealie pips and horse manure. He included mealie pips in grout to seal a cavity long before it was common procedure and used donkey manure because of its fibrous nature, in a cement grout 7 The freezing of the pilot tunnel at Du Toit’s Kloof preparatory to the construction of the Huguenot main running tunnel 8 Tripod dropping a 40 t pounder, the only time in South Africa that such a heavy pounder had been used and a world first in the procedure of dynamic substitution instead of dynamic compaction
Civil Engineering | May 2008 53 10 99
9 11 R P-D and Renée with their children in 1998: Megan, who, in the educational field, is regarded as an authority on children with ADD; Janice, also in education, who took the initiative to launch Protec in the Cape; and David, who is well known in the environmental field, especially as the publisher of Enviropaedia 10 R P-D and Renée in 2005 at the South African Academy of Engineers banquet at Kelvin Grove 11 R P-D holding a sample of jet-grouted cobbles converted to an in-situ concrete by the jet grouting process used at Hobie Beach, Port Elizabeth. The sample demonstrates the success of the process
sulting practice that provided a problem-solving and trouble- shooting service within the civil engineering and geotechnical fields. From the start, he was as busy as ever, the monitoring of all the anchored structures on the national road network being one of his commissions. By this time he was a qualified arbitrator and a fellow of the South African Association of Arbitrators, having passed the association’s exams in third place and outshining the younger members on the course. Eventually he acted as mediator, con- ciliator and arbitrator, as well as chief witness in several major disputes, and had the satisfaction of seeing these settled just before or during hearings. He also heeded the call by his professional peers to commit his extensive knowledge to paper by registering for doctoral studies at the University of Pretoria. Repeating the rigorous heard him raise his voice or use derogatory language to any of routine he followed in his arbitration studies, he got up at five his staff, no matter the seriousness of the matter, or who was every morning to put in a few hours of work before going to the responsible. He would always sit one down in his office and dis- office. As usual, Renée was at his side, proofreading the 520- cuss the matter to the point of a cordial resolution.’ page dissertation. His thesis, ‘Grouting in Southern Africa’, was This attitude was an offshoot of the culture of quality and submitted in 1991, gaining him his PhD in Civil Engineering. integrity that prevailed in GEL. ‘It was an unwritten law that Using an unconventional modification of the jet grouting we simply did not lie to clients and consultants,’ R P-D com- system in bouldery material – initially testing his theory in a mented. ‘It is so easy for an operator to make a foundation glass-fronted container filled with rocks and sand – R P-D solved investigation look better than it really is. The whole staff knew the problems engineers had encountered over a pier foundation that if anyone lied, he would be fired immediately. We eventu- of a jetty at Hobie Beach, Port Elizabeth. At a conference in New ally acquired the reputation of being quasi-consultants, because Orleans, where he presented a paper on this work, the eminent civil consultants would ask us for our advice on solutions for American geotechnical engineer Emilio D’Appolonia lauded it difficult geotechnical problems.’ as ‘an inspiration of how revolutionary work should be done by experiment followed by execution’. ‘Of course, jet grouting in RESOLUTELY CONTINUING bouldery material is now commonplace,’ R P-D remarks. He retired from the LTA Group in 1987 and ‘to keep out of As the geotechnical member on the panel of experts over- mischief’ he formed R Parry-Davies & Associates, a small con- seeing the construction of the Letsibogo Dam in Botswana, he
54 Civil Engineering | May 2008 directed the grouting, which was carried out by an interna- tional contractor. ‘These people had never previously come across my system of recording grout takes that enabled one to see the whole picture at a glance.’ In 1997 R P-D and Renée bade farewell to Johannesburg and moved to Hout Bay in the Cape. ‘I thought that my workload would dry up, but that just didn’t happen.’ He continued his work for the Department of Transport, moni- toring anchors throughout the country, and investigating anchored structures and cuttings for the South Peninsula Municipality throughout its region. He still commuted regularly to Johannesburg, inter alia to discharge his masonic obligations to the chapters in his district. By this time the highest honour in Freemasonry, the 33rd degree, had been conferred on him. Having become involved with the Hout Bay and Llandudno Heritage Trust, he cut his way through loads of red tape to have a replica of Thomas Bain’s tombstone placed in a prominent position on the rerouted Victoria Road above Llandudno. ‘It was unveiled on Heritage Day in 2000, and in deference to Bain’s Scottish ancestry, I arranged for a piper to liven up the proceedings.’ He was appointed specialist advisor for the stressed strengthening of two old reservoirs on Table Mountain, built in 1896 and 1906, a project that won the SAICE Western Cape Branch Award for Technical Excellence in 2001. In 2003 he was appointed specialist geotechnical advisor on the restoration of Chapman’s Peak Drive, with the emphasis on ground anchoring to support the half-tunnel and to tie back the concrete structures. The project won the SAICE Civil Engineering Award for technical excellence that year. At the awards presentation ceremony in 2004, R P-D was elected an honorary fellow of SAICE. ‘This is the highest honour that can be bestowed on a civil engineer in South Africa. Mike Shand said it was the only time that he saw me stunned into silence.’ Although he has slowed down in retirement, he still makes every second of his life count. He is currently docu- menting some of the professional developments he has pioneered, and is passionate about the conservation of our planet that is so much at risk because of man’s avarice. ‘If I could express a wish, it would be to be remembered as one who cared for our fragile planet, a competent geotechnical civil engineer, and a humanist.’
He was appointed specialist advisor for the stressed strengthening of two old reservoirs on Table Mountain, built in 1896 and 1906, a project that won the SAICE Western Cape Branch Award for Technical Excellence in 2001. At the awards presentation ceremony in 2004, R P-D was elected an honorary fellow of SAICE. ‘This is the highest honour that can be bestowed on a civil engineer in South Africa. Mike Shand said it was the only time that he saw me stunned into silence’
Civil Engineering | May 2008 55 On the move
1 2
1 Viwe Qegu 2 Gill Owens with C&CI MD Dr Graham Grieve
First woman on Vela VKE board Viwe Qegu has recently joined the board of consulting engineering firm Vela VKE as a non-executive director. Born in South Africa, Ms Qegu is a city planning scientist by profession and holds a master’s degree in City Planning and a BA (Law) degree. She worked at the Development Bank of Southern Africa (DBSA) as a trainee project manager, after which she practised as a city planner with the Centurion Town Council (now Tshwane Metropolitan Council) for seven years. She progressed to the position of a chief development planner, this being the highest planning posi- tion in the city. Professional highlights include being a co-founder and board member for Women in Housing and also serving as a board member and trustee to various organisations. She previously received an award as the Femina Woman of the 90s in recognition of achieve- ments in the sporting industry within South African society.
Gill Owens retires after nearly 30 years with C&CI Well-known construction industry personality Gill Owens recently retired after nearly three decades of service at the Cement & Concrete Institute (C&CI). Gill joined C&CI as librarian in 1978 when the institute was still known as the Portland Cement Institute, and based in Richmond, Johannesburg. After her appointment as C&CI marketing services manager in 1999, Gill assumed responsibility for the marketing support func- tion of C&CI, including the promotion of the Information Centre; production of publications, newsletters, and monthly reports; public relations; and maintaining the C&CI website. She also edited Concrete Trends, the C&CI’s quarterly journal which received a 2007 ‘Highly Commended’ Sappi PiCA Award. In her retirement, she will run her own new venture, Gill Owens Editing Services, and in this capacity will continue to edit Concrete Trends. She is currently also engaged in the latest revision of C&CI’s definitive reference publication, Fulton’s Concrete Technology.
56 Civil Engineering | May 2008 c on c re t e m a t t ers Cellulose fibre reinforced cement fails University of Pretoria strength tests as a gravity piping material
Tests conducted by the and 300 mm long sections for diameters as recommended in the Nutec literature, University of Pretoria’s Civil Engineering in excess of 300 mm. Table 1 of SANS 819 is taken into account, the equivalent D- Department reveal that the crushing (Edition 3.2) gives the required crushing Load values are 27, 40, 60 and 80 kN/m2 strength of cellulose fibre reinforced ce- strengths for the standard Series 1, 2, 3 respectively . ment (FRC) as a gravity piping material and 4 as 40, 60, 90 and 120 kN/m2 re- Based on the SANS 819 standard, a fails to meet several requirements laid spectively, when they have been in water pipe with a 600 mm nominal diameter down by SANS 819:2001 (Edition 3.2) for for at least 48 hours. It should be noted should take a load of at least 7 kN this type of gravity conduit. that these are ultimate requirements and (24 kN/m) for Series 1 and 11 kN The PIPES Division (Pipes, not proof load requirements, as given by (36 kN/m) for Series 2 pipes and only Infrastructure Products, and Engineering the standard D-Load requirements for one of the 600 mm FRC Series 2 pipes Solutions) of the Concrete Manufacturers steel reinforced concrete pipes. When tested met the crushing requirement. The Association (CMA) believes FRC pipe the ratio of ultimate to proof load of 1,5, minimum crushing strength required for has several other shortcomings (referred Table 1 Measured properties of pipes to below) which cast doubt as to its role as a gravity piping material and has sub- Sample OD ID Length Wall Dry weight Wet weight Moisture mitted related comments to the South (mm) (mm) (mm) (mm) (kg/section) (kg/section) absorption (%) African Bureau of Standards (SABS). Furthermore, the CMA’s PIPES Division A1 677 603 300 36,4 37,8 41,8 10,6 is of the opinion that some of the claims A2 678 603 305 36,2 37,1 41,6 12,3 about the performance of FRC gravity pipes appear to be at odds with some rep- A3 676 603 293 36,6 37,1 41,2 11,0 utable information sources. These claims A4 677 603 303 36,3 37,8 41,8 10,7 are also discussed here. FRC was first introduced in the 1980s B1 501 450 298 24,3 20,0 21,2 6,2 to manufacture asbestos-free flat sheets B2 501 450 298 24,5 20,0 21,4 7,2 and has subsequently been applied to B3 501 450 300 24,5 20,1 21,4 6,5 gravity pipes and other products previ- ously manufactured with asbestos. Semi- B4 501 450 301 24,3 20,2 21,5 6,5 rigid FRC piping was recently introduced C1 346 301 196 21,2 7,2 8,2 13,2 with wall thicknesses up to 20 % thinner than gravity piping made of steel rein- C2 346 302 198 21,2 7,3 8,2 12,9 forced concrete. C3 346 301 197 21,2 7,2 8,2 13,9 The tests conducted at the University of Pretoria centred on the crushing C4 345 301 199 21,4 7,5 8,4 12,1 strength of 24 FRC pipe samples using D1 236 200 195 17,8 4,0 4,6 14,9 SANS 819 (Edition 3.2) as the standard. D2 236 200 200 17,7 4,2 4,7 13,7 Conducted in September 2005, the tests used sample material which included D3 236 200 202 17,5 4,1 4,7 14,4 200 mm long pipe sections with nominal D4 237 200 200 17,6 4,1 4,7 14,5 diameters up to and including 300 mm,
Civil Engineering | May 2008 57 Table 2 Strength of pipes tested wet strength as high as 50 MPa and the Sample ID Length Wall Failure load Strength highest strength calculated for the pipes that were tested dry is 41,8 MPa. These (mm) (mm) (mm) (N) (MPa) results do however clearly indicate that A1 603 300 36,4 10 800 16,23 the pipes are significantly stronger when tested dry than when tested wet. The dry A2 603 305 36,2 10 400 15,53 behaviour is significantly more brittle, as A3 603 293 36,6 10 600 16,18 can be seen from the comparative graph A4 603 303 36,3 12 000 17,95 in figure 1. It is often assumed that because B1 450 298 24,3 10 700 26,95 FRC piping is lighter it can be installed B2 450 298 24,5 10 200 25,29 faster. This is not necessarily the case. According to the CMA’s PIPES Division, B3 450 300 24,5 10 900 26,84 FRC pipes can often take far longer to B4 450 301 24,3 10 700 26,58 install, especially if the installation takes place in poorly bedded installations or C1 301 196 21,2 6 100 21,06 unstable soils. C2 302 198 21,2 6 500 22,18 Unlike concrete pipes, which are largely self-supporting, FRC pipes re- C3 301 197 21,2 6 800 23,25 quire support from the surrounding soil. C4 301 199 21,4 7 200 23,94 Furthermore, FRC pipes are made in 5 m D1 200 195 17,8 7 650 25,59 sections and weigh essentially the same as the 2,5 m sections in which concrete D2 200 200 17,7 8 100 26,84 pipes are manufactured. This means that D3 200 202 17,5 7 600 25,34 the same equipment is required for the installation of both types of piping. D4 200 200 17,6 7 500 24,99 Other claims made about FRC pipes are that they offer superior chemical Table 3 Strength of pipes tested dry and abrasion resistance, better hydraulic Sample ID Length Wall Failure load Strength characteristics and design parameters. In fact, according to the CMA, FRC piping (mm) (mm) (mm) (N) (Mpa) absorbs much more water than reinforced A5 603 302 34,6 14 400 23,7 concrete (RC) piping and is therefore A6 603 300 34,4 14 200 23,7 more likely to be vulnerable to penetra- tion and attack by aggressive chemicals. A7 603 300 34,0 12 100 20,7 Tests conducted by the University of B5 450 301 24,6 12 900 31,3 Texas at Arlington, USA, in which actual service conditions were simulated, indi- B6 450 301 24,6 12 700 30,9 cate that FRC pipes lose up to 4,8 times B7 450 301 24,4 12 800 31,5 more wall thickness than RC pipes. The CMA’s PIPES Division says that C5 301 202 21,3 9 300 30,6 because FRC pipe is usually 20 % thinner C6 302 200 21,3 9 000 30,2 than an RC pipe, any decrease in wall thickness is liable to have a far more C7 301 200 21,6 12 800 41,8 damaging effect on structural strength D5 200 198 17,8 11 300 37,2 properties. D6 200 197 17,6 11 000 37,1 Moreover, the division notes that ex- cessive abrasion at the entrance to storm D7 200 199 17,5 10 800 36,6 water systems will also have a detrimental effect on hydraulic capacity. Abrasion Series 4 pipes with a nominal diameter load in excess of 15 kN/m but were unable resistance, wall thickness, strength of 300 mm is 7,0 kN (36 kN/m) and only to achieve anywhere near the requisite specification and a factor of safety on FRC one of the four sections tested met this crushing strength standard of 45 MPa. piping are all elements which should be, standard. These tests were repeated on dry pipes, but are not clearly spelt out by FRC manu- Table 1 gives the measured properties none of which had the requisite strength facturers. of the pipes used for testing purposes. of 50 MPa. In fact the best result achieved It is said that FRC piping has a low Sixteen pipe sections were tested wet was 41,8 MPa. manning value of n = 0,011 and that and these tests indicated quite clearly that For the wet and dry test results refer this ensures vastly improved hydraulic FRC pipes are significantly weaker when to tables 2 and 3. characteristics over RC piping. In reality wet. They were able to support a crushing None of the pipes tested had a the manning ‘n’ value for RC pipe is also
58 Civil Engineering | May 2008 1 1 Comparative draft 16
14 is immersed in water and subjected to 12 sustained loads. According to the CMA no specifica- 10 Wet 600 tion exists for the types or quality of fibre 8 used in the manufacture of local FRC
Load (kN) 6 Dry 600 piping. The reinforcement of the piping is therefore not specified at all. By contrast, 4 all the constituent materials, for example 2 sand, stone, reinforcement and cement,
0 are specified in reinforced concrete pipes. 0 10 20 30 40 Another concern is that SANS 819:2006 only applies to fibre reinforced De ection (mm) of pipes up to 1 000 mm diameters. There is no standard for larger-diameter fibre reinforced pipes. 0,011. However, because designers must of this safety margin is required to com- Reinforced concrete pipes have a take the difference between laboratory pensate for the fact that the safety factor proven life of 100+ years and the struc- testing and actual installed conditions is only based on a proof load as opposed tural performance is not influenced nega- into account, ‘n’ values of 0,012 and of to an ultimate load. Furthermore, it says tively by wet conditions. On the contrary, 0,013 are usually specified for actual de- it is well documented that FRC pipes lose concrete strengths improve in wet and signs using both materials. strength when wet and suffer long-term moist conditions. A safety factor of 1,5 is claimed for strength loss under sustained loading. ENQUIRIES FRC pipes thereby offering the specifier SANS 819:2001 requirements call for a safe, proven alternative which will per- strength loss to be no greater than 5 %. Concrete Manufacturers Association form under high loading conditions. In Australia, FRC piping manufacturers John Cairns The CMA’s PIPES Division says much indicate a loss of 50 % when their piping T 011-805-6742
Civil Engineering | May 2008 59 The amphitheatre on Kronenburg Estate Practical and attractive seating arenas constructed
Since earliest times, humans have over the world. made it so successful at creating small to felt the need to gather around a focal This block, the 4x4 step block, is part medium-sized seating arrangements. point to relax, negotiate and entertain of Terraforce’s large range of hollow core, At the end of last year, the block was each other, and since earliest days this reversible retaining wall units that offer successfully used at the Tourism Centre has been made possible by seating arenas the most versatile segmental retaining in Kayamandi, Stellenbosch, to create an or amphitheatres. Today, these struc- system in South Africa. They require eye-catching amphitheatre – a simple tures are still very popular, except that low hardware input for manufacture, neatly curved seating area required the method of construction has become low transport costs and low inventory for viewing performances around a easier and building material more varied requirements at sales outlets. Being courtyard. Following the success of that and versatile. hollow, yet strong, less concrete is needed project, two more arenas have recently One of the more cost-effective ways to do the job when compared to solid been completed. Both were installed by to build a seating arena is to use precast, block systems. Dassenberg Retaining, a Terraforce- solid concrete units or interlocking Initially, the 4x4 step block was in- approved retaining wall installer, who was concrete blocks that are relatively easily tended for low retaining walls and smaller also involved with the Kayamandi project. transported and installed. In addition, steps, but soon became very popular not The first amphitheatre to be com- concrete is durable, doesn’t burn and only for stairway access, but to provide pleted is situated on Kronenburg can be readily repaired or recycled. Most comfortable, practical stairs and seating estate, between Paarl and Wellington. products on the market offer some sort arrangements at leisure amenities and Conceptualised by Robin Barnes, ar- of benefit, but the most all-rounded, and school sport facilities. The blocks can chitect with JHP Architects and Town increasingly popular, is a specialised stacked up without mortar, interlocking Planners, it has become the ideal social segmental concrete block developed at the corners to form gentle curves and gathering place. According to Barnes it by Terraforce, a local concrete product varying wall angles, but it is by turning is designed on the same principal as the licensor with manufacturing outlets all the unit on its side to create steps that has traditional Greco-Roman amphitheatre
Civil Engineering | May 2008 61 Seating arena at the Berg River Dam
and experienced, virtually the same, by each person sitting at any position within the amphitheatre. Says Barnes: ‘We decided to use the 4x4 step block system as it gave us flex- ibility in the radius we required and the ease in construction that it provides. The blocks fit together nicely and provide the correct anthropometric sizes for seating and staircases. Ultimately the client was provided a facility that could be used for weddings, musicals and seminars, whilst maintaining a cosy and intimate atmos- phere within the amphitheatre, with the mountains as a backdrop. The project is a definite success; it not only works acousti- cally, but is aesthetically pleasing as well.’ Designed on strict guidelines supplied where acoustics work on the principle the bounds of the stepped stair tiers of by Terraforce the amphitheatre is built that sound travels upwards. The centre the amphitheatre. The people sitting on on a sturdy concrete foundation, followed of the circle would be the origin of the the tiers also absorb the reverberated by a row of concrete filled L11 retaining sound, whether it be a play, a musical or sound and have a dampening effect on the blocks, laid to the specified radius. Next, an oration. echoed sound. The clarity and quality of the 4x4 step blocks, filled with wet con- The sound travels outward and up- sound is thus carried in concentric sound crete, were set – on top of the L11 blocks ward without losing much energy within waves to each part of the amphitheatre – in groups of four to allow for the inser-
62 Civil Engineering | May 2008 tion of two 1,5 m long Y12 reinforcing Retaining, it is situated on the eastern seeing that the Berg River Dam is the bars, which facilitated the setting out of bank of the Berg River Dam which cap- first dam in South Africa to be designed, the radius. Behind each L11 and 4x4 block tures water in the upper reaches of the constructed and operated in strict accord- is a 400 mm wide layer of 3 % cement Berg River and will augment the supply ance with the guidelines of the United stabilised sand, with space for a 350 mm of water to the City of Cape Town by Nations World Commission on Dams. If wide strip of 50x100x200 Corobrik clay 18 %. It filled for the first time in July last you see at how the block and pavers blend pavers. The above steps were repeated year and boasts the highest concrete- in with the surrounding landscape, you until the desired height was reached. faced, rock-filled dam wall in South can easily see that no other product would The steps running down each side of Africa. Hugo Pienaar, quantity surveyor have been viable, especially one that is so the amphitheatre were easily incorporated for Dassenberg, says that the seating versatile and durable.’ by doubling up with rows of 4x4 step arena will provide visitors with a com- Construction of the arena proceeded blocks. Finally, the arched screen wall fortable viewing platform to sit and ad- the same way as with the Kronenburg am- across the open side of the amphitheatre mire the panoramic view of surrounding phitheatre, except for an increased radius was added, causing the reflected sound to area and the vast expanse of water. and a flared design at the edges – instead enhance the direct sound waves therefore In terms of landscaping, the down- of intrusive end walls – that provides in- adding to the total sound quality and stream face of the dam wall, visible from creased stability to the structure. Another giving the added advantage of a stage and the main road into Franschhoek, has interesting detail involved creating corner back stage area. been re-vegetated with indigenous flora. pieces for the two 90˚ bends. Says Pienaar: The second seating arrangement This ensures that the dam and associated ‘We simply took a 4x4 block and cut it at was initiated by Hans Roux of Grinaker- structures do not contrast with the sur- a 45˚ angle to form the two pieces that LTA who, with Group Five, WBHO rounding landscape. Pienaar says that this were then joined together with cement and Western Cape Empowerment is the reason the Terraforce 4x4 step block slurry. Finally, we have just been given the Contractors (WCEC), forms the Berg was chosen for construction of the seating go-ahead to create U-shaped stormwater River Project Joint Venture (BRPJV) arena: ‘A lot of money was spent rehabili- channel, using the same Corobrik pavers, that was awarded the R550 million tating the area, with new topsoil being around the entire radius of the arena contract for the construction of the placed and fynbos planted. Everything to prevent structural damage in case of dam. Conceptualised by Dassenberg was very environmentally conscious, heavy rains.’
Civil Engineering | May 2008 63 Text Phumudzo Baloyi Goba (Pty) Ltd [email protected] www.goba.co.za language fo c us : t shivenda The role of civil engineering in a changing environment
In this article, the author describes were installed at closer walking distances. more challenges that continue to confront his experiences from the time when he grew This has certainly changed and improved the people in the area. These include a lack up in the area previously known as Venda people’s quality of life. Instead of walking of adequate resources and skills to maintain until the present. long distances to fetch water, people could the facilities. In the early 1980s this area was under- now use their time for other activities. This Although there is infrastructure for serviced and lacked adequate water supply all was made possible by civil engineers, the supply of portable water to many and other services. As a result most of the who have contributed to bringing about an households, the supporting infrastructure people sourced water from rivers, fountains improved quality of life. that enables continuous uninterrupted and boreholes. Although the water was not Things continued to improve to the supply is inadequate. This is very similar purified, it was fit for drinking because there extent that some of the communities have to experiences in across the country and was less pollution in the river systems. running water in their yards, which is a vast indicates that our resources are limited. It With time, some communities started improvement on the situation in the past. is therefore important that everyone takes to receive services and communal taps However, these improvements came with care of these limited resources through
64 Civil Engineering | May 2008 conservation and awareness of the scarcity affected many areas including road infra- significant part of South Africa’s fruit, of resources. structure, which has deteriorated in many this could be used as a starting point An added challenge is that since instances and requires re-construction. ■ Attracting appropriate civil engineering skills people now have access to clean water, The following issues need to be ad- There is a need to come up with strate- the rivers are being neglected and they dressed as a first step towards resolving gies to attract civil engineers with are not an option for sourcing water the current situation: much-needed skills who have histori- anymore. Maintenance of existing infra- ■ Stimulating the local economy This could be cally been responsible for delivering a structure is a major challenge because achieved by promoting decentralisa- visible service the demand for skills, as well as urbani- tion and encouraging firms to open ■ Training and development Providing pro- sation, is depleting the skills base. factories in the area. As the area is spective students with bursaries and The lack of skills and resources has known very fertile and produces a similar support Musivili inzhiniara kha nzulele ine ya dzulela u tshintsha
Ili linwalo li nea zwidodombedzwa zwe munwali malo. Fhedzi izwi zwo ri zwi tshi itea ha vha na inzhiniara zwi kwama masia manzhi sa dzibada a zwi guda musi a tshi alutshela kha la Venda u dzikhaedu dze dza vha hone. Idzi dzo vha dzauri dzine na dzone dza khou sumbedza u toda u swika zwino. naho vhathu vho wana tshumelo, dzitshomedzo lugisiwa. Izwi musi zwo tangana na u shaeha ha Munwali ori a tshi aluwa nga tshifhinga tsha a dzo ngo lingana uri dzi nga thusa vhathu masheleni, zwi khou humisela murahu mvelap- minwaha ya gidi da tahe fumalo, vhathu vho vha vhothe nahone kufarelwe kwa idzi tshomedzo a handa i re hone kha la Venda. Zwine zwa nga vha tshi wana madi milamboni, zwisimani kana kwo lingana zwa sia hutshi vha na dzithaidzo. thusa kha u lugisa thahelelo dza vhadivhi na magwedzhoni ngauritshumelo ya madi o kunak- Naho hu na tshomedzo dzothe midini masheleni zwi nga vha zwi tevelaho: isiwaho yo vha i saathu u wanala kha mivhundu minzhi dza ndisedzo ya madi, madi a konda u ■ U tutuwedzwa ha zwa vhubindudzi Izwi zwi nga minzhi. Naho madi aya o vha a songo kunakisiwa, wanala ngauri madamu ane a vhulunga madi konadzea nga u bviswa ha dzifeme dzi tshi o vha a tshi nwea asina malwadze. Izwi zwo kon- na dziphaiphi dza u a disa madi vhathuni a zwi bva kha dorobo khulu dza iswa kha dorobo adzwea ngauri milambo yo vha isina mashika. swikeleli u thusa vhathu vhothe. Izwi a zwo ngo thukhu dzingaho sa Venda. Shango la Venda li Musi maduvha a tshi khou di ya phanda, fhambana na zwine zwa khou itea kha la Afurika divhelwa u vha na lupfumo luhulu musi ri tshi vhathu vho thoma u wana dzhitshumelo dzi Tshipembe hune tshumelo ya dzula i tshi shotha. ya kha zwa vhulima. Ili sia li nga shumisiwa sa ngaho sa madi e a disiwa tsini ha vhathu nga u Ndi ngazwo zwi zwa vhuthogwa uri vhathu vha line la nga bindudziwa khalo. Vhubindudzi vhu dzheniswa ha dzibommbi dza zwitaratani. Izwi divhe na u funzwa u vhavhalela madi nazwinw- nga sia hu na mvelaphanda zwa ita uri vhutshilo ha vhathu vhu khwinisee. evho zwi ngaho izwo. ■ U kungiwa ha vhadivhi vha mushumo wa vhusivili Vhathu a vho ngo tsha tshimbila dzinyendo Inwe ya dzikhaedu ndi yauri ubva tshe madi inzhiniara Ngauri zwi khou vhonala zwauri hu khulu vha tshi ya u ka madi milamboni zwa sia o kunakiswaho a disiwa vhathuni, milambo na na u shaeha ha vhadivhi vha mushumo, izwi vhe na tshifhinga tshinzhi tsha u ita zwinwe zwisima a zwi tsha thogomelwa nahone a zwi zwi toda uri zwi dzhielwe nzhele. Zwone zwi a zwithu vhtshiloni havho. Zwothe izwi zwo kon- tsha shumisiwa sa kale. U thogomelwa ha dzit- konda u wana vhathu vha divhaho mushumo adzea nga u shela mulenzhe ha dzisivili inzhiniara shomedzo dzine dza vha hone zwi sumbedza zwi uri vha takalela u ya fhethu hune ha kha di dze dza itisa uri matshilo a vhathu a khwinisee. inwe ya dzikhaedu. Nga u shaeha ha vhathu vha bvela phanda. Zwo tea uri he sedziwe ndila Zwithu zwo bvela phanda na u kwinisea divhaho mushumo wa sivili inzhiniara na u tuwa dza u kunga vhathu vho raloho u swikela vhathu vhanzhi vha tshi vha na madi ha vhatukutuku vhane vha vha hone vha tshi ya ■ U funziwa na u bveledziswa ha vhathu U funziwa midini yavho zwe zwa sumbedza mbelaphanda dzidoroboni khulwane zwo sia dzitshomedzo dzi ha vhathu zwi nga konadzea nga zwi fanaho khulwane kha vhathu musi hut shi vhambedzwa sina vhathogomeli vha divhaho mushumo wavho. na u rumelwa ha matshudeni zwikoloni uri vha na maduvhuni a minwaha ya gidi datahe fu- U shaeha ha vhadivhi vha zwa vhusivili gude mushumo wa sivili inzhiniara
Civil Engineering | May 2008 65 IN BRIEF placement of the toskane due to their extreme weight and having to be placed 35 m from the breakwater. The harbour had to be widened to allow space for the crane to operate from and the JV then used Sika ViscoCrete-20HE for their SIKA STRENGTHENS site batch concrete to rebuild the harbour wall. The armour units were placed to specific HERMANUS BREAKWATER x and y coordinates based on a theoretical packing density. The units were individually PRECAST TOSKANE positioned using an electronic total station.
The picturesque seaside town of Hermanus INFO was the location for a major harbour refurbish- www.sika.co.za ment project which involved a variety of Sika’s high-quality, innovative products and systems. The Department of Public Works ap- pointed Consulting Engineers Ninham Shand who determined that as a result of the existing harbour being weakened, more than two and REGION LOOKS TOWARDS a half thousand new toskane would need to be manufactured to replace several deficien- ZIMBABWE’S POWER PLANTS cies and to augment the existing toskane in order to strengthen the breakwaters and make In a move that could alleviate Southern the harbour safer. Africa’s struggle to cope with the growing de- The contractors (a joint venture between mand for electricity, while helping Zimbabwe Sea & Shore Projects and Civil & Coastal with its chronic shortage of foreign exchange, Construction) used 21 000 l of Sika ViscoCrete- neighbouring countries have proposed recapi- 20HE in the construction of the 2 650 precast talising some power stations and coal mining, concrete toskane that would make up the reported IRIN. breakwater for Hermanus Harbour. Sika Eskom, Anglo Platinum, and the Botswana ViscoCrete-20HE is a third-generation, high- Power Company have shown an interest in performance superplasticiser that is especially Zimbabwean thermal power stations located suitable for the production of concrete mixes in the capital, Harare, in Bulawayo, the second which require high early strength develop- largest city, and in Munyati, near the town of ment, powerful water reduction and excellent Kwekwe in Midlands Province. flow characteristics. It acts by different mecha- Anglo Platinum, which has been nega- nisms; through surface adsorption and sterical tively affected by power outages in its home effects separating the binder particles, the country, has asked to be allowed to export following properties are achieved: electricity to South Africa as part of its pro- ■ Pronounced increase in the early strength posal. development, resulting in very economic In February, the Southern African stripping times for precast and in-situ con- Development Community (SADC) taskforce crete on implementation of power projects held ■ Extremely powerful water reduction, re- an emergency meeting in Botswana on the sulting in high density, high strength and – this meant the contractors could refill state of energy supply in the region, attended reduced permeability for water, etc moulds quickly and fulfil their contract obliga- by ministers of energy, at which a resolution ■ Excellent plasticising effect, resulting in im- tions in time. was adopted to source funding for the energy proved flowability, placing and compacting The production schedule for the precast sector. behaviour units was between March and April 2007 and The meeting heard that if this resolu- ■ Reduced energy cost for steam-cured pre- the construction period for the placing of tion were not implemented, development cast elements the toskane in the breakwaters was between would be stifled, and that the region required ■ It is especially suitable for the production of September 2006 and June 2007; this was com- US$46,4 billion for long-term development self-compacting concrete pleted timeously. of the energy sector, while US$5 billion was ■ Improved-shrinkage and creep behaviour The contractors needed to attain a certain needed to complete current energy projects ■ Reduced closure times for repairs of roads, standard density and a high, 2MPa tensile early by 2010. runways and harbours strength for rapid removal of the items from Tomaz Salamao, SADC executive secre- Each toskane weighed 20 t and some 12 the moulds. This was accomplished using a tary, was quoted in the media saying: ‘The toskane were produced per day. In winter the dosage of 0,4 % bwc ViscoCrete 20HE and current electricity supply demand balance in moulds were stripped the same day without 400 kg/m2 RHPC to achieve early strength. the SADC region is precarious, as evidenced steam curing and transported after 24 hours The JV purchased a specialist crane for the by the recent frequent recurrence of black-
Civil Engineering | May 2008 69 outs and load shedding in virtually all the According to senior officials in the en- transaction adviser contract. countries of the SADC mainland as well as ergy industry, Eskom was ready to pump up ‘The development cost is approximately Madagascar.’ to US$25 million into the Hwange Colliery R1,3 billion,’ says the technical director of Vela Since the beginning of 2008, South Africa, Company (HCC), Zimbabwe’s sole coal pro- VKE, Dave Gertzen. The 175 000 m2 develop- Namibia and Zimbabwe have been among ducer, to ensure reliable and uninterrupted ment will comprise two parking basements; the countries in the region hit by widespread coal supplies if the proposed takeover of the four four-storey low-rise office towers; the planned and unplanned outages, affecting three thermal stations, with a combined po- Foreign Services Institute – which is respon- every sector of the economy. tential of 500 MW, was formalised. sible for the training of DFA delegates – and Eskom has blamed the blackouts on a state-of-the-art conference centre to host heavy rain in the coal-producing parts of the international conferences such as the African country, which it said had affected the quality Union and SADC. of coal required for its coal-fired plants, and The design embraces communication breakdowns at several of its key generating between the various branches, which are plants. currently scattered around the inner city. In HEAD OFFICE CAMPUS a ‘blocking and stacking’ exercise and under Money needed the guidance of Foreign Affairs, branches are Ben Rafemoyo, chief executive officer of the FOR DEPARTMENT OF to be located for maximum interaction with Zimbabwe Electricity Supply Authority (ZESA), each other. recently told the Parliamentary Portfolio FOREIGN AFFAIRS To this end, vertical access is provided Committee on Mines, Energy, Environment by escalators and lifts in core areas and and Tourism that his organisation needed The work on the new head office campus horizontal access is via an internal ground US$3,8 billion for a complete overhaul of obso- of the Department of Foreign Affairs (DFA) floor street and skywalk bridges on the upper lete equipment to generate at least 2000 MW has commenced with an early works contract. floors. ‘We are placing the branches which needed to meet national requirements. Work started at the end of May 2007, after a belong together, next to each other,’ says ‘We are in a precarious financial posi- bidding process of more than two years. Total Gertzen. The new DFA campus will house ap- tion because our tariffs are very low,’ said construction should be completed by March proximately 2 200 personnel, including DFA’s Rafemoyo. The Hwange power station in 2009. growth forecast over the concession period. Matabeleland North Province was producing The new HQ is situated on the corner of The development also includes twin five- 280 MW, when it could generate 750 MW at Tom Jenkins Drive and Soutpansberg Road, in star boutique guesthouses to accommodate maximum capacity. Rafemoyo said the Kariba the residential suburb of Rietondale, Pretoria. foreign dignitaries. One is a new lodge-style hydropower station on the Zambezi River, The 15 ha government site is immediately guesthouse situated in a remote corner of on the northern border with Zambia, had a north of the Daspoort Ridge, in the shadow of the main campus site and the other is the generating capacity of 750 MW, but was pro- the ministers’ residences atop the ridge. existing guesthouse in an upmarket suburb of ducing 720 MW. The project is being undertaken under Pretoria, which is to be refurbished to match ‘Other power stations can generate the government’s public private partnership the new guesthouse in standards and ameni- 170 MW but are not generating anything be- initiative, and offers ground-breaking op- ties. cause of lack of coal. The older the machines portunities for participation by previously Dave Gertzen says the proposed develop- at power stations, the more breakdowns we disadvantaged sectors of the economy. ment underwent a rigorous public- experience and these are costly to repair.’ Vela VKE has been the technical adviser Zimbabwe generates 1 000 MW, against to the transaction adviser and the DFA since Artist’s impression of the new head office for the a daily requirement of 1 500 MW, and imports the end of 2003, when SPP were awarded the Department of Foreign Affairs 40 % of its electricity from the Democratic Republic of Congo, Mozambique and South Africa. The country has had to resort to power rationing because of the shortfall, which has affected many industries, homes, schools and hospitals.
Coal shortages Zimbabwean power stations have also been affected by coal shortages. Energy Minister Mike Nyambuya confirmed that failure to pro- vide enough coal and ageing equipment had affected the country’s ability to fulfil its energy requirements. Although energy shortages were pre- dicted in 1995, nothing was done about the looming problems. ‘Most of our machinery for energy generation have not been replaced in the last ten years,’ he said.
Civil Engineering | May 2008 71 participation process as part of environmental ‘Overall, the average annual growth scoping. A number of government and local stands at 4,3 % with 98 029 qualifications GOVERNMENT SHOULD authorities such as the Department of the awarded in 2004 with the largest average Environment and Tourism, the South African annual growth in the field of Business and BE MORE PROACTIVE IN Heritage Resources Agency and Tshwane Management Sciences – 8,4 % or 29 702 Municipality had to put their stamp of ap- qualifications awarded in 2004. DOING BACKGROUND proval on the development before permission ‘Two areas of concern regarding the was granted to commence construction. lowest average annual growth are in the SCREENING ON EMPLOYEES ‘The public and private parties are to be fields of Social Sciences at only 2,4 % (39 781 commended on the speed at which these qualifications in 2004) and Engineering The public servants who have recently been simultaneous processes were concluded,’ Sciences and Technology, which has been exposed as qualifications cheats were merely confirmed Gertzen. identified nationally as a field of scarce and the tip of the iceberg and many more are critical skills, also only 3,5 % (11 038 qualifica- waiting to be discovered should the govern- tions in 2004). There is a need to improve the ment get its house in order and implement INFO senior certificate pass rate, especially in Maths widespread background screening. Dave Gertzen and Science, in order to fulfil the require- Ina van der Merwe, CEO of Kroll Vela VKE Consulting Engineers ments of this field.’ Background Screening, one of the largest [email protected] Snapshots of availability data were taken qualifications verification companies in South in 1994, 1999 and 2004. The total availability Africa, said both government and the private figures (the total number of people with sector had a major problem with bogus their highest qualifications in each field qualifications. – the South African ‘pool’) grew by 116,9 % ‘At the moment about 14 % of all qualifi- (from 542 398 in 1994 to 1 176 496 in 2004). cations sent to us for verifications turn out to IMPORTANT TRENDS The largest growth was in Business and be false. That includes everything from matric Management Sciences with 153,8 % growth certificates to degrees and diplomas.’ IN QUALIFICATIONS of the field since 1994. Three years after efforts began to verify public servants’ qualifications, employees are AWARDED TO WOMEN Availability figures by group resisting the process and government depart- ‘By 2004 the proportion of black graduates ments are dragging their feet about getting it AND BLACK LEARNERS (African, coloured and Indian) of the total done, a report tabled in Parliament found. pool was 46,3 %, up from 23,8 % in 1994 with Sixteen public servants below middle While the proportion of qualifications black graduates best represented in the Social management level – most of them in the awarded to black and women graduates has Sciences and Humanities field (56,3 %) and Western Cape – had so far been found to increased substantially, a key area of concern worst represented in the Engineering Sciences have fraudulent qualifications, according to is that the majority of these qualifications are and Technology pool (31,2 %,),’ explains the Public Service Commission’s (PSC) report. still at relatively low levels – 6 and 7 on the Yvonne. To date only seven provincial departments National Qualifications Framework. and two national departments had completed This is according to research published By gender the process of background screening. Sixty in SAQA’s second Trends in Public Higher The proportion of women graduates in provincial and 19 national departments were in Education Report (1995–2004), based on South Africa increased from 41,0 % in 1994 the first stages of the job. statistics from the National Learners’ Records to 48,4 % in 2004 with the smallest share for ‘The main constraints cited were staff Database which SAQA collates and manages. women graduates in Engineering Sciences and resistance to the verification process and that The report covers trends in Public Higher Technology – only 16,0 % in 2004 but, even staff take too long to provide proof of qualifi- Education from NQF Level 6 upwards in 54 then, up from 10,3 % in 1994. cations where it is requested,’ read the report. work-related categories across five broad It recommended that heads of depart- fields of study, tracked for the decade from By field of study ment took charge of the process. 1995 to 2004. ■ Largest growth Business and Management ‘A strong message needs to be sent to Yvonne Shapiro, the director of the NLRD Sciences 279 803 in 2004 (153,8 % growth of all public service officials that the verification at SAQA, identifies some key points of interest the field since 1994) of qualifications is part of the anti-corruption from the report. ‘The proportion of qualifica- ■ Lowest growth Health Sciences 117 303 in programme of government, and that lack of tions awarded to black learners (African, 2004 (91,6 % growth of the field since 1994) compliance may adversely affect the ethical coloured and Indian) increased from ■ Engineering Sciences and Technology credibility of the department as a whole.’ 44,9 % in 1995 to 63,7 % in 2004. However, 143 062 in 2004 (92 % growth of the field The focus on employees below middle most of this is still at the lower levels – since 1994) management was the third phase of the 67,2 % at Level 6 and only 47,7 % at Level 8 process. In 2001 senior management had and above. Similarly, women’s share in quali- their qualifications verified. fications awarded increased from 47,9 % in In 2003 it was the turn of middle manage- 1995 to 56,0 % in 2004 but most is still at the ment. A confidential list of people who had lower levels with 55,8 % at Level 6 and only falsified their qualifications was part of the 43,1 % at Level 8 and above. resulting report.
72 Civil Engineering | May 2008 Van der Merwe said government should headings: 40,5 million tonnes of firewood each year introduce incentives for employees who ■ Asset and Project Management which destroys over 400 000 ha of forest. dragged their feet or who were reluctant to ■ Water Sanitation and Environmental Environmental activists have been lob- hand in their qualifications for verification. Management bying the government to create a desert ‘We know from our own experience over ■ Transportation, Roads and Storm water control commission and pass a federal bill to many years that qualifications cheating has ■ Operations, Maintenance and address desertification, but parliament has become something of a national sport be- Refurbishment not yet taken action. cause it is so easy to get away with it. Unless An abstract – and preferably also an introduc- government and companies in the private tion – of their intended paper must be sub- Effects sector become proactive about the verifica- mitted electronically on the website One of the worst affected areas is Yobe tion process this will remain a problem.’ www.imesa2008.org.za. State in northern Nigeria. ‘Sand dunes She said the main problem with em- Papers will be accepted on the under- are encroaching at a rate of 30 hectares a ployees who were holding positions with standing that the main author (or a co-au- year, taking over [entire] villages,’ Suleiman bogus qualifications was the fact that they thor) will personally attend the conference as Garba, project manager of the federally were unable to perform effectively because a fee-paying delegate and present the paper, funded North East Arid Zone Development they lacked the educational skills and that this in the required format and according to stipu- Programme, told IRIN. could be one of the reasons why certain gov- lated deadlines. The symptoms are erosion, rain short- ernment departments provided poor service Giving recognition to well-engineered ages and drought, said Basiru Buwa Adamu, delivery to the public. projects for infrastructure, this year’s confer- Kano state director of afforestation, adding ‘They are also depriving honest em- ence includes the biennial IMESA Excellence that the livelihoods of over 55 million people ployees who went to the trouble to achieve Awards for Outstanding Infrastructure are threatened, more than the combined diplomas or degrees of jobs that should right- Engineering Projects. The objective of the population of Mali, Burkina Faso, Senegal and fully be filled by them.’ award is to portray the art and science of civil Mauritania. Kroll has in the past done background engineering, illustrating how the profession A report of Nigeria’s National screening for several government depart- finds answers to challenging infrastructure Meteorological Agency released in early ments, Van der Merwe said. problems. March 2008 said the rainy season in the north ‘It is vital that government be ardent in has dropped to 120 days from an average of their pre-employment processes. All prospec- INFO 150 days 30 years ago and as a result crop tive employees should be screened so that Marianne Oosthuizen yields have dropped by 20 %. the government maintains a high degree [email protected] For environmentalist West this is an indi- of vigilance to guard against qualifications cation of global warming. ‘The Himalayas and cheats,’ she said. the Arctic provide a cooling effect to global climates and temperatures that are becoming INFO warmer by the day with the ice melting, Leon Smith NIGERIA: THE DESERT IS FAST causing climatic change globally. While the Kroll other parts of the world are experiencing 012-644-4000 ENCROACHING, BUT WHY? flooding and excessive rainfall, here we are 082-881-5232 experiencing rain shortages and drought.’ Experts agree that an estimated 35 % of land that was cultivatable 50 years ago is now Deforestation desert in 11 of Nigeria’s northern states, but Yet for Adamu, Kano State’s director of af- what they are not so sure about is why. forestation, ‘global warming pales into insig- ‘These are indications of global warming nificance [compared] to the environmental ANNUAL IMESA CONFERENCE which the world must grapple with,’ Igiri problems which deforestation engenders’. West, a Kano-based environmentalist, told The forests in northern Nigeria have al- CALL FOR PAPERS IRIN. ‘The level of industrial and vehicular most vanished and lumberjacks keep moving emissions [in industrialised countries] is so steadily southwards. Nigeria has the world’s The 72nd annual IMESA conference – recog- high that they are capable of drastically af- highest deforestation rate of primary forests nised for its contribution to knowledge sharing fecting the climate [in northern Nigeria].’ according to a 2005 UN Food and Agriculture in the local engineering industry – will be held But Kabiru Yammama of the National Organisation report. ‘[This] puts it on track to at the Sand du Plessis Theatre Complex in Forest Conservation Council of Nigeria disa- lose virtually all of its primary forest within a Bloemfontein, from 29 to 31 October 2008. grees: ‘Deforestation constitutes 75 per cent few years,’ the report said. The conference theme this year, of the environmental problems in northern Crop yields of farmers in more south- ‘Innovation – The Road to Service Excellence’, Nigeria,’ he said. erly states such as Niger, Plateau, Kogi and covers a broad spectrum of topics to allow all ‘The increasing need for wood fuel for Benue have dropped and, at the same time, disciplines in the municipal engineering field domestic use has caused the rapid depleting northerners are migrating south looking for to make a contribution. Prospective authors of trees which has caused increasing havoc greener pastures for their cattle, and that wishing to present an oral and/or poster on the environment and put farming activi- leads to increased conflict over land. presentation at the conference are asked to ties at great risk.’ submit it under one of the following session Yammama said the population burns over
Civil Engineering | May 2008 75 ECOLOGICAL COASTAL CITY IN CHINA EVOKES THE DUTCH WADDEN SEA
The engineering consultancy DHV has been commissioned, together with the Chinese planning institute Qinghua and the Arup consultancy from the UK, to carry out a prestigious coastal and urban development project in China. The coastal city is to be built on an area of 150 km2 and will soon have to provide space for one million inhabitants. DHV won the assignment by including in its concept for the area an island and lagoon structure, which reminds one of the Dutch Wadden Sea. in size to that of the Port of Rotterdam. The Artist’s impression of Caofeidian new coastal city The concept allows for the creation of fresh port, which is being further developed very groundwater in a sustainable manner for use rapidly, is today partly operational. Initiative (NTI) Intsimbi programme, a TDM in the city’s green spaces. The international The Caofeidian New Coastal City is the manufacturing industry intervention, if we do jury, consisting of experts from Italy, Sweden, second large coastal project that DHV has not address the current situation proactively and China, complimented the proposal for designed for China recently. In the other case, the industry will suffer from job, skills and the way it combined coastal development, the Chinese were enthusiastic about the economic loss. energy, water, and transport into an attractive Delta Diamonds, a 75 km2 polder land-recla- This decline has caused industry demand urban design. mation project for the urban, economic, and (such as the local automotive and packaging The new coastal city will be built in ecological development of Tianjin, China’s industries) from the local TDM supplier base Caofeidian, an industrial zone in North China largest import harbour. This project is cur- to fall below 20 %. It is estimated that the on the Bohai Sea. ‘Caofeidian has to become rently under way. TDM demand for these key sectors will ex- the model for China and the rest of the ceed R6 billion by 2008. world of a Chinese ecological coastal city,’ Van Dyk says while several initiatives are says Dick Kevelam, DHV’s advisor on coastal under way to revitalise the TDM sector, many development. Because of the coastal loca- of these initiatives are running programmes tion in a salt-water area, and because of the aimed at National Qualifications Framework limited rainfall in the north of China, there (NQF) levels 2 to 3. is little fresh water available for the future BALANCING GRADUATE ‘Despite good intentions, this model is inhabitants. ‘One of this project’s challenges flawed. By pumping people into NQF levels 2 is to capture and recycle fresh water in as a OVERSUPPLY AND THE and 3, we’re setting them up for employment sustainable manner as possible,’ according to in production and maintenance of a declining Kevelam. SA SKILLS SHORTAGE industry. However, what we really need to be At high tide, the outer islands off the doing is getting the top people into place coast form a sea defence wall that offers flood Cognisant of South Africa’s skills so that the industry can win large contracts protection for the lagoon, which is located shortage and the oversupply of matriculants which will directly create jobs for people at behind. The city is to be built on islands in the and graduates, the South African Tool, Die and the lower levels. We need to create a balance lagoon. The islands will be raised a number Mould (TDM) sector has taken steps to correct and this means addressing all skills levels and of meters above the salt water, by drawing this imbalance, a process that is going to take attracting specialty skills such as design engi- sand from the lagoon. The lagoon design about eight to ten years before it starts to bear neering to the industry. will restore part of the original tidal mud-flat fruit. ‘If our specialist design engineers come coast in this area and will save those areas The TDM sector is a key support sector up with ground breaking innovations that that still exist. to manufacturing, one of the main drivers help us win contracts, then we’re looking ‘In this case we’re not creating land in of export growth. However, the sector has at becoming a competitive player in the the sea, rather we’re returning water to the declined over the past 20 years as a result of industry again. And the people who have land in a controlled manner, thus re-creating a deterioration in capacity, the skills base and entered the industry at NQF levels 2 and 3 will a natural dynamic,’ as Kevelam puts it. In technology status. have jobs and the opportunity to grow into order to adapt the Dutch know-how as much In recent years the TDM industry has more meaningful roles,’ says Van Dyk. as possible to China, DHV is working very suffered a steady decline due to a critical The Intsimbi programme, a joint closely on the project with its colleagues in shortage of skills, underinvestment in new Toolmaking Association of South Africa Shanghai. equipment and a lack of enterprise develop- (TASA) and Department of Trade and Industry In early 2009, the city’s construction will ment. According to Dirk van Dyk, national (dti) initiative, was established to address the begin next to an industrial port comparable programme manager of the National Tooling gap in the country’s various skills interven-
Civil Engineering | May 2008 77 1
tions. It is tackling the issue in two stages. value chains and select components for pro- ‘The first stage – and our short-term focus duction where we have potential for a high – is aimed at strengthening the capacity of degree of success. existing initiatives at Further Education and ‘It is cause for concern that increasingly Training [FET] colleges, technical universities, more tools, dies and moulds are being national universities and private sector initia- imported by local manufacturers. We are, in tives. This will see the provision of upgraded effect, exporting jobs rather than developing curricula and state-of-the-art equipment to and retaining those skills in the country,’ he the various institutions,’ says Van Dyk. says. The second stage is about customised The NTI will dramatically improve the interventions such as youth-based marketing circumstances of the TDM industry over the campaigns, maths and science re-orientation next eight years and transform it from being 2 programs, student assessment tool develop- a net importer to becoming a net exporter. ment projects and specialised skills develop- South Africa has the human and raw material ment. ‘This is where our medium-to-long- resources to do this. ‘All we require is the cor- term focus is,’ says Van Dyk. ‘There is a 70 rectly focused investment in skills, equipment per cent drop-out rate at technical colleges and enterprise development.’ and universities and we need to introduce a higher level of assessment to determine can- didates’ potential success in technical careers.’ In addition, this stage is about directing engineering generalists into specialised skills areas. ‘A mechanical engineer will not be able to come up with plastic injection moulding LIVIERO SHOWS ITS METTLE innovations, but if the engineer is trained as a design engineer for a specific technology plat- ON THE GAUTRAIN form such as a specialist designer for plastic injection moulded tooling, there is a much Liviero Civils, one of the fastest-growing 1 Rebar the tunnel boring greater chance of success,’ says Van Dyk. civil contractors in South Africa, is showing its machine (TBM) base slab A mining skills project is being piloted in mettle on a range of works on the Gautrain at 2 Chistopher Coleman, site agent, Limpopo Province where a skills GAP filling the Rosebank and Sandton stations. in the Rosebank Tunnel Portal project is currently under way. The project At Rosebank, Liviero has been responsible has called on the private and public sectors for the drill and blast (DB) and tunnel boring to cooperate and current partners include machine (TBM) base slabs, which in essence industry partners Sandvik, Lonmin, Cambrien enable the drilling of the Gautrain tunnel University, TASA and various SMMEs, and to the north and the south of the Rosebank government partners the Department Station. of Economic Development, the dti, the ‘These slabs entail the supply and fix of SOLAR-POWERED Department of Education and various aca- all the related rebar, the concrete formwork demic institutions. and the actual pouring of the concrete,’ says AUTOMATIC LAWNMOWER! The Limpopo project will see skills GAP Stuart Knight, Liviero Civils MD. elimination in two main areas, the first being The base slab varies from 700 mm to It makes perfect sense that nobody would maths and science focused re-training for 1,7 m thick and requires more than 3 000 m3 want to mow the lawn when it is raining, so technical careers. This is for school leavers of concrete and 500 t of rebar. the premise for a solar-powered lawnmower is and candidates with prior learning. The The duration of the works was in the a no-brainer. second area is specialised mining skills region of 18 weeks and was completed in Husqvarna has launched the world’s first training that is not currently being serviced January 2008. automatic electric solar-powered hybrid ro- by any of the tertiary education institutions Charles Wright, Liviero Civils contracts botic lawnmower. The new lawnmower offers such as training in specialised mechanised director, says the Gautrain is certainly one users happy to pay the £2 000 price tag the mining tooling skills. of the largest civil construction contracts in promise of never having to mow their lawn Van Dyk says the initiatives are aligned South African history and while the scope of again … with the Joint Initiative on Priority Skills works is sometimes extremely challenging This lawnmower can clear 2 300 m2 of Acquisition (JIPSA) model. ‘In some instances from a practical point of view, the major chal- grass and is programmable to work only at South Africa may import teachers to ensure lenge on the contract is the collaboration certain times or days of the week. It has a bat- that our learners receive globally recognised between the myriad parties involved in the tery life of approximately 40 minutes before a skills,’ he says. wide range of tasks. 40 minute charging time juices it up, but on a Van Dyk says the sector cannot afford to ‘There is a great deal of interdependence sunny day, its cutting time can be extended train specialised engineers across the entire on this job and I am pleased that the Liviero by another 50 %. spectrum of industries. ‘We cannot produce team has proved itself to be a very efficient all components. We need to identify specialist and effective partner on this contract.’
Civil Engineering | May 2008 79 UPGRADING OF SANDKRAAL ROAD, GEORGE
The upgrading of Sandkraal Road in George, Western Cape, was identified through the George Mobility Strategy project, in which certain corridors in George were earmarked for upgrading to proper public transport routes. A public transport route was identified for provision for minibus taxis and buses, as Engineers, comprises the upgrading and wid- reducing walking, cycling and travelling. The per the proposed restructuring of the George ening of a section of Sandkraal Road between total length of the Sandkraal Road Corridor is Public Transport System, non-motorised trans- Industrial Street and the N2 Interchange ramps. approximately 7,8 km. port, and dignified spaces. In general the objective is to improve the The commencement date for this project The project, which is being managed environment in order to stimulate business was 12 February 2007 and the contract period by the George office of Vela VKE Consulting developments closer to communities, thus is expected to run for 56 weeks.
Date Event and CPD validation number Presenters/venue Contact details 18–19 June – Midrand Engineering and Construction Short Chris Wentzel Cindy 23–24 June – Witbank Contract [email protected] 17–18 July – Durban SAICEcon08/00311/11 18–20 June – Cape Town Project Management with Microsoft Andrew Holden andrew@classic–sa.net 25–27 June – East London Project SAICEproj07/00181/10 21–27 June – Gauteng The Application of Finite Element Method Roland Prukl Dawn Hermanus 6–12 September – Gauteng in Pratice [email protected] 8–14 November – Gauteng SAICEstr06/00018/08 6–12 December – Gauteng 22 June – 19 July Construction Management Programme www.cpm.sun.ac.za Alett Slabbert University of Stellenbosch SAICEcon07/00199/10 [email protected] 23–27 June – Johannesburg Design of Masonry Structures A N Fried; H C Uzoebgo; [email protected] 30 June – 2 July – Durban O J Kanyeto [email protected] www.wits.ac.za/enterprise 1–3 July – Heidelberg Engineering & Construction Contract Chris Wentzel Cindy 12–14 August – Witbank SAICEcon07/00201/09 [email protected] 17–18 September – Midrand 14–15 July – Durban Business Finances for Built Environmental Wolf Weidemann Dawn Hermanus 11–12 November – Gauteng Professionals [email protected] 24–25 November – Gauteng SAICEfin06/00004/08 17–18 July – Durban Handling Projects in a Consulting Wolf Weidemann Dawn Hermanus 6–7 November Diarise– Gauteng Engineer’s Practice [email protected] SAICEproj06/00003/08 22–23 July – Gauteng Basic Construction Estimating & Planning Phil Watson Sharon Mugeri SAICEcon06/00106/09 [email protected] 4–5 August – Gauteng Soil Stabilisation J Coetzee [email protected] SAICEtr06/00024/08 18–20 August – Port Elizabeth Environmental Management for the S Ballot SARF Roads [email protected] 27–31 October – Gauteng Tailings Course 2008 Beric Robinson [email protected] SAICEot07/00232/10
24–26 November – Cape Town 2nd International Conference on www.civil.uct.ac.za/iccrrr [email protected] Concrete Repair, Rehabilitation and Retrofitting
For more information on courses, venues and course outlines please visit http://www.civils.org.za/courses.html or contact [email protected]
80 Civil Engineering | May 2008